Much of what you will hear about SEO is parroted non-sense. I have heard advice concerning brand postal addresses parroted around quite a bit. I will try and make sense of it for you. Please forgive me if I cover things you already know. Today happens to be one of those days with a lot of interruptions so I may have missed something. Still, I think I got the bulk of the infromation you need.
There is no metric to drive rankings tied to contact information though contact information is a requirement for branding ones site. More on this.
In your question you are asking about using pages that speak specifically to the brands that you sell. This is a good idea and very common. However, you also mentioned postal addresses and potentially using mark-up for the brand mention as well. Including and marking-up the postal address is not such a good idea. This will become self-evident in a bit. I am in favor of mark-up. Your mention of marking up the brand and I assume in conjunction with a rating may be a good idea though I think I would preserve this effort for the product pages rather than exclusively for any brand page. Having a page for each brand makes sense for semantics and please do not think in terms of keywords. In order to make your site stronger for a particular brand, you can use more subtle techniques for making your site stronger without having to create pages that rank high or capture search traffic.
Here is an answer that I like that gets into semantics a bit: Why would a website with keyword stuffing rank higher than one without in google search results? Please ignore the title.
The take away is that you can use semantics across pages to make your site stronger for brand based searches without misdirecting the user.
There are metrics that are related to branding, however, that is branding for your site and not branding for the products you may represent or sell. Still worth reading.
To explain, Google will not consider a site to be a brand without a proper level of contact information. Sites do not have to have mark-up but it sure does help Google to identify who you are. Prior to using mark-up, Google would look for company information using a parser model reading pages top-to-bottom focusing on traditional pages such as About, Contact, Company Info, etc. Another place for this would be the header or footer of any page. Using pattern recognition, addresses, phone numbers, fax numbers (by extension), e-mail addresses, names, etc. could all be easily recognized. Using mark-up ensures that Google receives this data correctly and therefore while there is no ranking metric for marking up contact information, there is the added benefit of having that data trusted more.
There are 46 metrics that I count for branding a site.
Short of sending branding signals for your site, any other page that discusses a brand that is not owned by the site is content and will be treated as such. One way to distinguish a brand owned by the company site is to mention that brand and provide contact information for that brand on the traditional pages such as About or Content. This is where things get a little complicated, however, brands related to the company will have some overlap in their information making it rather simple to identify a brand belonging to a company and company site. A major part of this contact information. This is why you should not add contact information for a brand. There have been cases where brand ownership has become confused.
It is not uncommon that a company that sells products of a particular brand to provide information for that brand on a page. Again, this would be content. It is also a good idea. In this case, the page should have information that directly ties to user decision making and helping the user to trust the brand. Part of this would be information about the brand itself and likely links back to the brands company page (off site). This makes sense. Anything added to this page should be related to the brand to help users make decisions about their purchase. However, it should not confuse search.
It has been my experience that some sites will create pages with information that confuses search. If a search returns information that may be correct but not from the brand itself, the user could be disappointed. For example, the user may be looking for a support phone number while not being terribly knowledgeable of the company itself. The user may have landed on a page that does not represent the company and did not provide the information the user was looking for. For page such as this, searching for address information has returned a result in the SERPs that is not useful and the bounce rate increased by one. This may sound trivial, however the principle is the same. More on this.
There is a danger in confusing search with information that your page should not be found for. For example, I was searching for a particular Samsung TV model to compare prices. The bulk of the pages linked in the SERPs were for sites that for a variety of reasons could not satisfy my search. Some did not sell Samsung TVs and many others did not sell the model I was looking for. However, these sites had pages for these brands with model names and numbers that the company does not sell and never did sell. In fact, these were not product pages but other pages designed to confuse search. More bounce rate.
Besides user experience, bounce rate is a difficult thing to get a hold of. Bounce rate is one of two things: one, either the user was 100% satisfied with the search result and got their answer quickly (and this does happen); or two, the user was 100% dissatisfied with the search result and did not get their answer. There are categories of sites that satisfy the user search quickly and the list is short. For the remaining sites, controlling bounce rate is a matter of properly matching the site content and the search users intent. We read about this all the time on SEO sites but seldom does anyone really focus on this as a tactic. We all need to.
Crafting content for proper search results is an art and a science. I agree that you should add a page that explains the brand. It not only makes sense for the user, but may also help with conversion. Make sure you do not add details and information solely to capture more search users when the quality of the search user cannot be quantified. It is not about capturing users but rather users that convert. Your content must be geared toward that goal and forgetting this can have a price for both the user and yourself. Include just exactly what the user needs and nothing a user does not need. Do not confuse search results. In fact, it may be wrong to think in terms of this page for rank and search traffic. Your product pages are what needs to capture user interest.
