With regards to your personal trip, I would seriously consider not doing both Vancouver and Toronto, unless you really wish to spend a half/day or longer of your vacation in an airplane, plus lose three hours due to the time difference (essentially costing you a day).

Vancouver is really nice and you could split time in Victoria/Vancouver Island which is also beautiful. Victoria also has the Delta and the Marriott, which seem to treat members well if I remember the reviews correctly.

If you are in Toronto for three weeks I assume that weekends & nights will be free, which I think will give you a good taste of the city. You could also drive out to Niagara Falls, also with a number for Marriott hotels. Montreal is also doable from Toronto over a weekend on a quick flight (1 hr) out of YTZ if you are staying in downtown Toronto.