I called the AMA prior to my Canada/Alaska trip I’m currently on, and I was told the coverage is good in Canada.
As for the Gold Wing Road Riders Assoc. plan, coverage is also good in Canada. The membership card shows a separate phone number to call for assistance in Canada.
Now, here's the issue. I drove a tow truck years ago and so I have a little insight as to what happens when you call AAA. You talk to a AAA dispatcher that takes all of your info, including which tire is flat, what color is the bike and that it is, in fact, a motorcycle. AAA then calls one of their contractors that has the contract for the area where you broke down and their dispatcher calls one of their tow truck operators, gives them NONE of the information that you gave AAA and sends them out simply telling them that it's a black Honda. The driver shows up pissed off because he doesn't get much for AAA calls and he didn't know that he was picking up a bike.
I got lucky the guy that came out was experienced and I had a good conversation with him on the way back in his air-conditioned truck, but all-in-all I would probably consider AMA myself if it wasn't that I canceled my membership when they were fighting to pass a law that all bikes have their high-beams on permanently. (yes, some years ago now.) But the peace of mind that AAA gives me for the cars as well helps.