FNV works well on Wine with a couple of exceptions.
1. No sound for gunshots only(you can hear the slide and the action but no fire).
2. Cant use the 4GB patched version(this appears to be Steam's fault and not Wine's. Steam is doing some stupid checking on the executable.
As to other games YMMV. Some perform better some perform a bit worse than on windows and there are usually just little annoyances.