I think the phonebook access would depend mainly on the capability of the stereo. The phone will certainly allow for it, though you may have to allow the access the first time you pair the phone to the stereo. That's what I had to do with my car stereo...I have a Kenwood brand head unit.
I can't answer your question about voice commands though as I don't know which device those would be pulled from. I can't say my stereo does that...I think it may be a function of the stereo but not totally certain.