>>How does it work at Air Canada? Are the RJ pilots mainline Air Canada? How did it get that way?<<
It doesn't work at Air Canada... CALPA attempted to put the "regionals" on the Air Canada seniority list with retroactive dates of hire (as at SAS). AC pilots took a stand against this nonsense and left CALPA to form ACPA. Many of the AC pilots had left the regionals to join AC, they would have watched their buddies from the commuters come over ahead of them, so they bolted CALPA and kept their list intact.
At least, until now of course, ACPA accepted mediation yesterday to solve issues including merger of the Candian pilots (represented by CALPA) onto their list.