Don't know if you found the answer you were looking for, but I had the same experience. I took it to the dealer and they stated the GM had put out a "bulletin" or notice regarding this issue in July 2011 (#08-08-44-024). I also had the seller "promise" it had bluetooth, only to find out it didn't. The GM bulletin states that the only way to tell if your vehicle has bluetooth is to do what you've done, and if it responds as yours (and mine) did, it does NOT. While it was irritating and I felt like a dope taking it to the dealer for something it didn't have, GM didn't seem to think it a big deal. Their (biased) suggestion was to activate my Onstar (which I'm not because it's expensive). Unless you want and will use Onstar, your best bet is to buy your own Bluetooth device to install (or have installed) in the car. I have found a few that can be installed into the car that will utilize the radio/nav. system, but they range from $100-250. Sorry if this info is too late or if you've already solved your answers.
Dang, this is good to know. I just got my Traverse last night and was anxious to get my and my wife's phones paired with the Traverse BT. But it didn't recognize that command, so I guess I don't have it. We also just got brand new Verizon Motorola cell phones, and thinking those may be the problem too?
OK, any suggestions on 3rd party BT solutions??