It doesn't matter for the Volt. Since it has a range extender, there's no real need for fast charging. Just charging it every night from a 120V outlet will eliminate most gas usage for most people. If you run out of charge, it's an annoyance rather than a disaster.

I can't speak to the Bolt since I've never seen one.

I've test driven a bolt and done the diligence on it.

It needs 4 (FOUR) days to charge on a standard outlet. If you happen to own a house, you can have the higher amp outlet installed for like 2k.

Otherwise, good luck finding a fast charging station for GM cars. They don't exist.

It depends on your mileage. 4days to fully recharge from empty, if you are on a road trip (which you obviously couldn't do in a Bolt). But overnight it will charge 50miles, which covers local daily use.