I want to know if there is a centralised community site where all Hardware is listed in terms of compatability with Linux. Something like AppDB for Wine.
Centralized I don't think so.
But maybe this one is something you are looking for.
But there are some sites:
And the Debian Hardware Portal
And an older list
And most likely there are compatibility lists on every major distributions' site/forum. And some specialized sites like for TV-tuners