Probably not a great idea, but since you say that you are in YYZ or SFO, the non-stop options are bound to include AC and UA flights. And if the destination is most convenient to a major hub of any *A airline (AC, UA, CO, US), then that stacks the odds even more in your favor.

If the airline is DL or AA and you are more SFO based, then consider collecting the miles on AS, which has mileage partnerships with both DL and AA (so that you can concentrate your non-*A miles) and has a decent west coast route network, including service to all of SFO/OAK/SJC.