Trying to establish communication between PS3 controller and Arduino

Hey guys I'm working on expanding a project that I finished a few weeks ago.

I have a robot that I can control with my phone but now I'm trying to see if I can control this same robot with my ps3 controller.

The robot already has a bluetooth shield attached to it but I can't seem to get them to connect.

Here is the shield http://www.trossenrobotics.com/p/bluetooth-shield.aspx

The shield and the ps3 remote use bluetooth vs 2.0.

I've seen many projects already that do exactly what I want to do but they use a USB host shield with a bluetooth adapter plugged into the shield. Is this necessary if I already have a bluetooth shield?

Any insight?