10% Tuesday was an IGA thing first that Safeway copied, so that should remain. Also, it looks like Sobeys is the Air Miles supermarket in Quebec and Atlantic Canada, so that shouldn't be a problem either.
Looking at this locations list:
http://en.wikipedia.org/wiki/Sobeys#Locations, it looks like Alberta is really the only province where Sobeys and Safeway both have a prominent presence.
I had no idea there were 16 Sobeys in Calgary.