No idea - my parents were on UA, which I knew, and got miles for it - these I do not know, but they have tended to be TWA, UA, CO, and US. I have a pair of US flights that I have set aside for later next year to give them a try.

Could be any airline, and may or may not accrue mileage. It's not priceline, so that already seems to be okay by most airlines right now.

All I can say is, take a look at who serves those locations.