Not sure if this helps but when I had command on my C Class I had a lot of contacts in my phone (about 400). After the initial pairing it took over 30 minutes before the sync completed and I was able to see any contacts on the cars screen.
Whilst this was with an Android phone not my iPhone the same might apply to you.
Are you giving the phone plenty of time to sync or like me have you been sat there pairing and unpairing when nothing shows after a few minutes?
You might want to pair it and then leave it whilst you go for a drive in your new toy.