This depends on where you are looking for the goal conversions. If you look at Conversions > Goals > Goal URLs, all conversions will be attributed to the home page since that's where they literally occurred.
However, if you go to Behavior > Site Content > Landing Pages, you should see conversions attributed to the blog pages -- after a quick change to the report. Option 1: at the top of the page, between the segments and the graph, there is a list of metric groups with Summary selected; change that to the appropriate Goal Set. Option 2: in the header of the last three columns of the table there is a drop-down menu with eCommerce selected; change that to your CTA click goal.
If there are still no conversions showing against blog pages, there are two things to check:
Is the goal recording at all? Event tracking, goal definition, goal turned on, see your own clicks in the Real-Time report.
Do you need to set up Referral Exclusion in order for GA to consider the blog the same site as the homepage? You can track two different domains in the same GA account, but they will be treated as different sites unless you tell GA to treat them as one site.