Is it possible to outrank a keyword domain for example perthwinefactory.com.au (for the keyword perth wine factory) with my domain winecorp.com.au ? I have been trying for about an year now but looks like it is impossible, no matter what I try. (domains and keywords mentioned above are not from a real world scenario)
Of course you can. Any page can outrank any other page for any keyword regardless of domain names. There are lots of factors that affect the ranking of a page with keywords in the domain only being one of them. You don't control many of the factors that affect ranking plus a year is not a lot of time especially if the keywords are competitive.
This question list lots of (possible) factors affecting a page's ranking. Make sure your optimization efforts are maximized and be patient awaiting results.