I don't have a Bolt yet, but I tried this out when I test drove one. Apple Car Play only works via USB on the Bolt. You can certainly use navigation on the iPhone and have the audio stream via bluetooth to your vehicle speakers, but if you want to see the map on the car's screen it will need to be connected via USB. I believe only BMW has wireless apple car play right now.
No idea about android auto.
No idea about android auto.