score:9
Within US and Canada its $25, and they don't mention specifically that its only from the US to Canada, so I would assume that its both ways. To the best of my knowledge flights to/from Canada are considered "domestic" for all terms and purposes, so I see no reason why the luggage would be an exception.
Upvote:1
"within US and Canada" -> not crossing the border, so your departure and destination are in the same country (say Atlanta to Buffalo, NY)
"U.S./Canada and Caribbean" -> departure and destination in different countries (so say New York to Montreal).