In park, press the talk button and say Bluetooth. If it knows the command (say help) then you should be able to pair most phones built within the past ten years or so. You'll be able to answer a call by pressing the button, ending a calling by pressing the button and saying "End Call", making a call by saying Call or Dial. The Call command relies on the directory built-into the unit, not the phone. I've never been able to get it to link up with the phone directory...and these days if I make the mistake of allowing the Google Assistant in the phone to use a connected Bluetooth microphone for input...more often than not the 'GM lag' impairs any useful input.
In theory allowing Google Assistant to unlock by voice means you could ask it to initiate a call (from whatever information it has access to) and it switches to the Bluetooth headset once the call is made. But in practice the interior so noisy it doesn't work reliably. Stick to answering calls and watching out for VW drivers.
The 2010 interiors were built from parts developed in what? 2006 or earlier? So the dogStar/head units were way out of date when they shipped, with only a buggy low level Bluetooth Headset Profile - and not the A2DP required for streaming. Over the years Bluetooth stack updates in Android have caused, fixed and 'accommodated' various issues.
P.S.: Blame XM for the lack of an input on the radio...appalling...
