Referring to the following message: http://www.winehq.org/hypermail/wine-users/2004/12/0091.html
USB in iTunes is said to work "with a lot of fiddling about".
Your best resource may be: http://www.codeweavers.com/site/support/docs/crossover-pro/troubleshooting#ITUNES-IPOD
I think it explains the steps pretty clearly, and would be pretty useful even to non CrossOver Wine users (don't worry about not having cxipod, it doesn't do anything that can't be done manually, and I'm pretty sure it's all explained).
Cheers,
Jeremy
