If memory serves, Greyhound Air did indeed have a program that could be used for reward travel on its air or bus line. It could also be used for shipping cargo. I also seem to recall that you needed only 5 or so roundtrips to get a roundtrip reward ticket. A sample walk up one way fare from YOW to YWG (2 1/2 hr flight) was about C$180 all taxes in.
They also used 727 aircraft with noise reduction engine refits.