[Zammy-Sam]

I didn't really get the situation. You have a Mac at home that is connected to the internet. Now you are at a college and want to access your itunes files? Rendezvous is for local networks, if I am not mistaking it.
However, I don't know if this will be of any help, but remember you will need appletalk for rendezvous and appletalk can be active for only one network device. If I have appletalk on for my ethernet connection and I move to a wifi one, I will need to open the system preferences and change the appletalk support from ethernet to my airport card. Just a shot into the dark room..