In our legislation, we don't oblige anyone to use either one of those two terms, but if they are using them, they have to be accurate.
Now, of the two terms, “Made in Canada” and “Manufactured in Canada”, the latter is the more specific term. As long as the company that is making the claim can show that the product was actually manufactured here, that the product fulfills the 51% requirement and that its last transformation happened here in Canada, then they could certainly say either “Manufactured in Canada” or “Product of Canada”.