How much is the bonus? Sadly, 150K-180K is not unheard of. If you are single, want downtown living and not save a lot, Toronto could be a fine place to be. The job market is also slowly getting better. However, do note that Toronto is fairly high cost-of-living if you have kids (i.e. aspirations for a house with a yard; houses went up over 20% last year and they were expensive before that), plan to drive (check out the vision zero plan which reduced speed limits all over the city to an unreasonable level IMHO). The elite employers will likely pay you more (e.g. shopify, google, layer 6) but will of course be harder to get a job. Canadian immigration is also not the easiest (though the reputation may seem otherwise).
I have heard great things about Sydney. May I ask why you want to move? To me, Sydney sounds like the place I'd move to after becoming a millionaire (no snow, beaches, nature).