http://bugs.winehq.org/show_bug.cgi?id=24928
--- Comment #8 from Danellos trevor.w.philip@gmail.com 2010-10-28 16:33:00 CDT --- No problem
but as the blue did say, you SHOULD be able to max the settings in dx9 mode given that you do have the correct shader model and the right extensions. This could thus be a WINE bug.
Do note, however, that the OpenGL mode in WoW has only max support for shader model 2, so even in Windows you can't move certain settings beyond "fair". Sunshafts, new water, as well as shadows is also not available in OpenGL mode for WoW Windows client. In dx9 you should be able to max out everything though, as I just said.