First, is the coolant bottle showing low?
Second, if not, then might be from previous bleeding done at dealer.
Third, if it is, then there can be several potential places for leaks.
1. T-stat housing area
2. Exhaust valve area hoses.
3. Waterpump hoses/clamps in front down low.
4. Heat exchanger hoses behind engine.
5. Throttle body entry and exit hoses.
Any air bubbles will not normally cause leaks. Just possible overheating which can cause leaks from the bottle overflow hose.