I got NWN2 working fine, with minor graphics errors on Mac 7.2.1... including with MotB and SoZ expansions.
I got it to run better using a modified version of the CrossOver Chromium wrapper (cuz it has wine 1.1.20 in it, even newer than Crossover 8.0 beta), and it runs fantastic in that... grand, graphic errors gone. (hopefully Crossover 8.0 will fix these problems since its easier than making and using a separate wrapper)
The problem though, is there is a registry entry you have to enter for OffscreenRenderingMode = fbo in order for the expansions to not have graphical problems. So far on all Macs I've tested this on that have ATI graphics cards cannot draw the graphics right anyways. On nvidia Macs it seems to work great though. I've been playing NWN2 latest version with all the expansions fine.