There is no officially support Linux GPU client, and in all likelihood, there never will be. However, there is user-developed support for running the Win GPU client under WINE. You can learn more about it in the subforum at foldingforum:
Folding Forum • View forum - unOfficial Linux GPU (WINE wrapper) (3rd party support)
Unfortunately, you can't run the GPU client inside a VM because the VMware drivers don't support it. Again, most likely a "never will" scenario.
Note that native Linux SMP performance is quite a bit better than VM'ing it. But, even though the GPU/WINE combo only uses about 10% of a CPU core, for some reason it wrecks havoc on the kernel scheduling when run in combination with the SMP client, causing huge slowdowns for both. So, if running both SMP and GPU simultaneously, VM'ing the SMP client is really your only option I'm afraid.
That's why so many of us are hoping that SMP2 for Windows is going to be as good or better than the current Linux client.