Is it ever stated which cities belong to which factions?

I know Sentinel is Forbear, as well as Rihad and Taneth, and then Hegathe, Elinhir and Stros M'kai are Crown (I believe), but what about the other cities?

Unknown, as far as I know. You're aggregating data from a couple different time periods, so by the late 3rd era (or the 4th) allegiances might have shifted. For instance, the first PGE paints a much more Forbear image of Elinhir.