In regard to places to eat and beer time, while there are many reasonably priced (not much different than costs of nice meals in the US) restraurants that serve fresh seafood, I have one suggestion for simple old fashion BBQ Caribbean style. The Rib Factory downtown in the Mall overlooking the harbor is the best bang for the buck I've found. The full rack of pork ribs was approximately $11 and change last January and are the best ribs I have eaten anywhere (and being from Texas, I eat a lot of BBQ) and are consistently good as I have probably eaten there 10 times on our previous six trips. I usually have left overs for another meal later. Also, try a Polar beer (or two because they come in the little 8oz bottles and cans) although, for some reason I remember that the Rib Factory served them in larger 11 oz bottles. Its a good Venezuelan beer that can not be found in the States. The price of beer is generally a little higher in Bonaire than the US, but it deceiving as I mentioned earlier, most of it is sold in the small 8 oz containers, and so the bar price is about $2 to $2.5 a pop. You can get a case of Polar, Amstel or Heineken for around $20.
For drinking establishments, Karel's Beach Bar out on the pier in front of the Mall is probably the most lively night spot. They have nightly drink specials, as well as live bands on the pier on weekends. Also, this is where the KLM flight attendants hang out after the weekly DC 10 from Holland comes in.