There is no need to get vaccins for Bonaire. Despite of the fact that there are mosquitoes there is no danger for malaria.
There are several medics, a hospital with a decompression chamber and 2 pharmacies (boticá).
Salt water from the sea is processed into drinking water. It is of very good quality. Drink enough water, at least 1,5 liter per day!
Take precautions against the sun, especially between 11 am and 3 pm. Use sun blocks, sun glasses, a hat. And remember that the chances of getting sun burned increase on the water while surfing or snorkling.