The Ghibli does not support Bluetooth while connected via USB. Pretty sucky, but then this is technology shared from the steamy pile of Chrysler.
Reading your question again, you are asking if pandora is available over USB. No, only over Bluetooth and again only if your phone is not connected through USB.
This not only sucks because iTunes and Pandora are in effect mutually exclusive, but more because Pandora and charging your phone are mutually exclusive. What I've done is keep a permanent phone charger with a coupled USB hooked up inside the console's power outlet. This charger also has a nice LED light on it that illuminates the inside of the console, very functional and looks like it's an integral part of the car.