Bowfin are native to Ontario, and certainly were legal to keep when I lived there. They were sold in aquarium stores...and also bait shops! I don't know about other provinces, but each has its own rules and regulations. I very much doubt that they are illegal now.
Snakeheads? Years ago every LFS had a tank crowded with bright red-striped C.micropeltes fry; other species were seen very infrequently. My LFS owner mentioned something about not being able to ship Channa to Ontario and Quebec, but didn't mention other provinces. Again, you must check your local regulations.
This is Canada; we have enough things that really are illegal, in the aquarium field and everywhere else as well, without adding imaginary bans as well.