heh, true. It doesn't look good with the first letter capitalized, at least imho, and probably wouldn't alter the impression non-initiates would get. I tried putting "windows emulator" underneath, but it looks a bit out of place and kind of reduces the impact. It also makes it harder to scale down, at 50% of the size you can still read the "works with wine" text, but not the "windows emulator" underneath.
Maybe you could also mention Linux or use the penguin or whatever. So people that don't know wine at all maybe have a hint or at least get curious if someone states that his Windows App also runs on Linux.
bye Fabi