Ok well bum is the operative word. Basically I have tried a myriad of ways and I can't seem to get album covers working and this extends to the music explorer section. Also with further testing... Artist images aren't being picked up properly (it's just grabbing album art from the first music file in an artists collection). Also... play count doesn't appear to work nor does as of the visualisation, theatre view stuff. These seem to be the main failings.
That said if you turn off hte thumbnails and largely forgo the music explorer section (or accept it won't have pretty album art on your own music BUT album art does show up art for exploring the store), you're still left with a pretty nice player for mac. The "now playing" page looks great with all artwork as expected. The compact player looks fantastic too. It does play music fine and work otherwise as I would expect. I even managed to install lame mp3 converter and did a test conversion and that works fine too. Its so nearly there (not bothered by visualisation or theatre stuff) but the lack of proper artwork for artists or album covers thumbnails is such a shame... if that worked too it would be amazing. You can see album art on tracks being played... just not thumbnails.
Anyway... time to call time on this. Happy to share the version I have but be warned it isn't quite where I would like it to be. And it does install by literally dropping the file into your applications folder and launching it (no wine installer required) but uncompressed it is 1gig so quite big (Compressed it's 400meg odd). @Colch - Did you not experience the issues I reported? Amazing find btw... you were a bit of a genius figuring this out as I have tried so many ways to get it to work yet none have worked like yours. Will see if I can upload some images to photobucket to shwo what it looks like. Cheers.
PS you can see some images here
(ignore the genres you may see in one of the images as i am messing around with these... so there is no issue with these... if you're curious it's just the separator isn't compatible with musicbee but that is not a fault of the wine version (or any other version) and is easily fixed)