I use my IPhone plugged into the rear USB port also, the bike thinks it is an IPOD, I listen to pre-recorded music or PANDORA. PANDORA can be a little tricky, you have to have it playing before plugging it into the bike, and you do not have the normal PANDORA functionality of skipping a song and then if you loose the signal and PANDORA hangs up on you, you cannot get the IPhone to switch over to pre-recorded music. In the IPOD function you can use the bike's random selection mode to mix up the songs, just like if it there was a thumb drive plugged into to the USB port.
Florida Prowler # 46250
The Lord said; "Thou shalt have dominion over all of the animals, except of course the cat."
My therapist's name is Dr. Goldwing, she has the antidote for the blues.