I just took a code share flight YYZ-YUL-ZRH and was only allowed one checked bag on the Air Canada YYZ-YUL segment. I was told that AC AND LX hadn't come to terms on a baggage agreement?! So, the Swiss and Canadian government can agree on open skies but AC can't agree on a baggage agreement??!!
I ended up taking my second checked bag on board the YYZ-YUL flight and then checking it in YUL for the final YUL-ZRH segment.