As a former regional employee that got hooked up with US benefits for a bit, free flights are on US Airways and only US Airways, but once he has 6 months of seniority there are pretty good discounts on other airlines through ZEDs. He should have a better priority on US than he would as a regional carrier employee, however. Also, I think there is a $20/flight charge for parents (maybe it was $25?). To be honest, I would expect a lot to change in a couple years anyway.