Originally Posted by
hearna
to YEG, you can book it, ensure all fares are good, and if not, cancel within 24hours.
Or book CO/UA.... all fares earn 100%

That is the problem with booking codeshares. IIRC people have tried calling in to AC and even they can't tell you what the flight will map to in the operating carrier's fare buckets.
I guess you could call each operating carrier individually and see what fare bucket they show you in, but IIRC some people tried that without success as well.