If you can get to MIA by noon there's an Insel Air flight direct to Bonaire that leaves at 2PM on Saturdays. Otherwise it's probably a series of connections. There's also a United/Continental direct red-eye on Friday night out of IAH (Houston)
www.infobonaire.com has just about everything you need to know.
Where are you leaving from in Canada? Curacao is the same diving (almost identical - same reef 50 miles apart) but there may be better flight connections there. Also the shore dive entries are actually easier - most are off beaches or dive docks with facilities on the beach.
www.curacao.com
While Bonaire diving is equally easy, entries are often trickier over coral rubble and submerged ironshore in the surf-line. Unless you just dive the resorts or boat dive but you'll be missing the best reason to go to Bonaire if you do. Outside of the resorts there are no facilities at any dive site on Bonaire - sometimes you're the only people nearby. It's not a reason not to go, just be careful on entries/exits - and carry a cellphone in a submersible case - one thing about Bonaire shore sites is there's some casual theft so you don't leave anything of value in the vehicle.
A lot of people from Western Canada go to Cozumel, I think there's very good flights - either direct or just one stop. Check in the
Cozumel sub-forum for details if interested. It is mostly deeper drift diving though which may be something you'll want to wait until later to do - get more dives first.