I'm 99% certain that AC no longer interlines luggage for separate PNRs. You'll have to pick up your luggage at YYZ T1 (where the AC flight from YOW will arrive - dreadfully slow luggage service in YYZ), then find the (free) train/monorail (it's well marked) and get to T3.

Even with the oft-horrific delays in returning luggage, 3hrs should be plenty of time for transfer plus dinner.

I haven't been over to T3 for years, so I couldn't tell you what dining options there are there.