It's fine to mix wild and tank raised clowns together. Also note that just because a clown is tank raised doesn't mean it doesn't know what an anemone is. Think of it like cats and catnip. Some cats are attracted to it, and others are not.
Natural hosts for a BTA include maroon, clarkii, bicintus, frenatus, etc. but not the "Nemo" type clowns like percula and ocellaris. That said, many percula and ocellaris -- both wild and tank raised -- have BTAs as hosts.