Is there a bus from Nanning Airport to Quanzhou city ? If not, what is the recommended way to go?

Oh, they are too far apart, so no direct long-distance bus is available. The best way is to take a direct flight. The flights are scheduled at 12:00 on Tuesday, Thursday, and Saturday, and the trip takes about 2 hours.

Or, you can airport take shuttle bus line 2 to East Railway Station. Then, take a bullet train to Shenzhen North (about 4.5 hours). Upon arrival, take a bullet train to Quanzhou from Shenzhen North Railway Station (about 4.5 hours). :)