I have found references to a Fort Myers Southern Railroad with service to Bonita Springs. It began operating in 1925. The railroad was owned by Barron Collier.
I have found references to Seaboard Airline Railroad with service to Bonita Springs. An individual named Alex Grantt stated the above photo of was of a train depot owned by the Seaboard Airline Railroad.
.If anyone has more information about this please contact me