VortexBox advertises itself as an iTunes streaming source using the DAAP (Digital Audio Access Protocol) You can listen you music from iTunes or from an Apple network attached client such as an ipod touch. DAAP is an autodiscovery protcol so your VortexBox should just appear in iTunes. The VortexBox will appear in the “Shared” section on the iTunes sidebar.
The DAAP server in VortexBox rescans the mp3 folder every few minuets so if you add new mp3s or load a new CD it could take a while for them to appear.