Most of Bonita Springs is inland. Much of the coast there is a state park. If staying on the water is important, verify your location. You will have more options on the water in either Naples or Ft. Myers Beach. If you want to be between Naples and Ft Myers, that is where it is.
Sarasota is 80 or 90 miles from there.
If you like to shell, I might take a trip over to Sanibel as well.