There is no Chateau Lake Louise-like property on Bonaire. The only upper-end luxury hotel on Bonaire is Harbour Village (and it charges top end prices) and not much of a house reef. That said, there are some very upper end private properties with nice house reefs.
I think high end is, at least to some extent, in the eye of the beholder. What is important to you? Lush manicured grounds? 400 count sheets? An infinity pool? World class spa? Always present and helpful (but never intrusive) staff? Great art in the rooms? Large suites? Water slides? Warm muffins and fresh fruit when you surface from a dive? (Personally, I have always thought a dive butler would be great).
My advice: Think about what is important to you. Think about the tradeoff of time and money (cheaper means you can stay longer but may not enjoy each night as much). Start looking at options with that filter in mind. (I end up at the Carib Inn. The price - $100 to $160 a nght - means I can stay three weeks yet stay at a place I really enjoy with a good house reef. OTOH, I could stay longer at a place like GRI or shorter at a place like HV. All three of those -- and those are just examples, are there are many other solid options -- are good choices. It is all about what you want and what is important to you...