I just had a read over at winehq wrt this release;
http://appdb.winehq.org/objectManager.php?sClass=version&iId=21910&iTestingId=59019
That's mostly linuxcentric and what Mac entries are there
suggest OSX has troubles with the Steam release - I also
get the impression that the Steam version doesn't really
appreciate Ati videocards (an if this is so, it likely to
be somewhat worse in OSX due to driver difference).
This doesn't explain why it was working and now does not.
The only thing I could think you trying, is running the
game in windowed mode (or enable emulate a virtual desktop
in the Wine Configurator), and you could also experiment
with the Direc3D registry keys (although you might want
to leave UseGLSL=enabled with the Ati);
[HKEY_CURRENT_USER\Software\Wine\Direct3D]
"DirectDrawRenderer"="gdi"
"OffscreenRenderingMode"="fbo"
"RenderTargetLockMode"="auto"
"UseGLSL"="enable"
The various settings for these keys are documented he;
http://wiki.winehq.org/UsefulRegistryKeys
There is no ''magic' answer - experimentation is the only
way you'll be able to discover if any key (or combination
of keys) will work for you....good luck!
Cheers!