You know these sorts of bugs are hard to tell if they're a WINE bug or a catalyst bug. Have you filed a bug report at winehq? or searched for a similar bug?
e.g. (Ubuntu 9.04 x86-64 P8600 4GB mobility 4850)
wine 1.1.31 + cat 9.10 GW seems to work perfectly
wine 1.1.32 + cat 9.10 GW char selection screen garbled, flashing triangles all over the game play screen, X3 Reunion all sorts of weird distorted textures(think that this is the GW char sel screen problem) in gameplay, scrambled game menu, etc.
In the above cases I'm at leats partially inclined to blame wine...
Sager NP8250-S Core i7-4800MQ/780m/32GB/128GB SSD/750GB Scorpio Black/1TB WD Blue(7mm) (win7 x64 pro)
Acer Chromebook C720(i3-4005U/4GB) 128GB SSD(stable/crouton xfce)
DIY ASUS P9X79/i7-3930k/64GB/multiple multiple terabyte HDDs(mostly WD 10k)/780 Ti SC (win7 x64 pro/Ubuntu 14.10)
DIY ASROCK 990FX Extreme9/FX-9590/32GB/multiple multi-TB hdds/R9 280X
DIY ASUS A88X Pro/A10-7850k/32GB/R9 270