If I had a non diving spouse, unless it was one who wanted to sit by the pool all day, I'd choose Curacao. Having spend only a few hours there. There really isn't a lot to do on Bonaire other than dive. I've been to Bonaire probably at least 20 times; it's mostly diving. The beaches aren't that great either. There aren't any resort hotels (tho I think Marriott or someone is building one); they are all dive hotels.
Unless you did guided dives, or paid for boat dives, it might be difficult finding a buddy. Most of the diving is shore diving. You can always dive solo; it's mostly easy diving on the west side. One advantage of Bonaire, if you were willing to dive solo is that you aren't restricted to anyone else's schedule. There are some lovely condos with diving right off shore. You could pick up a tank and go out for an hour or so whenever you wanted.