That will depend on whether Cathay Pacific and Air Canada have a baggage interline agreement when on separate tickets. AC's website for their interline example actually uses CX of all airlines (https://www.aircanada.com/ca/en/aco/...-partners.html) but it doesn't say how it works for CX to AC when on separate tickets (the example it uses shows what would be a booking on a single ticket). So you may need to call CX or AC or try to research on CX's website to find out if they would interline your bag to AC on a separate ticket so that it is tagged MNL-HKG-YYZ. But if CX is unable or unwilling to tag your bag onward to AC for the HKG-YYZ leg and only tags it for MNL-HKG, you will have to claim your bag in HKG and recheck it with AC. I imagine this will also include clearing customs and immigration after arriving from MNL and then having to reclear immigration after checking-in with AC for the flight to HKG.