Just picked up my 2005 330Ci and YES! Indeed is it bluetooth supported as long as you got the Premium Package and have the Assist program installed with mic. Bluetooth is installed and ready to go. Works instantly with my bluetooth phone. Even imported my adress book.
The service manager gave me the simple documentation to pair my phone with my car as said that not all 2005's have it only those that were produced within in the last 2 months.