Mike, you must be the luckiest guy on the planet. Especially if you drink water from a source that you believe is safe because you've seen frogs swimming around in it. Keep in mind that those frogs eat many of the other insects and insect larvae that also survive in those waters, critters that can eat holes in your intestines and take up refuge in other body parts. There are loads of parasites in those ponds. Now, I have to admit it has been a long time since I was in the Bahamas, but if I recall, the municipal water supplies there were not all that safe. Yeah, you might get away with drinking tapwater, but that doesn't mean your immune system is any better than anyone elses - it just means you've been quite fortunate.
As for bacteria resistant to chlorine, I don't know of any. In fact, good old Clorox Bleach, especially in heavier concentrations, kills all living cells. It doesn't discriminate. When I was a young man and working for University of Maryland Hospital, one of the projects we were researching was trying to find a new antibiotic that would be effective on TB. We would pipette live TB into Petri dishes, then add tiny tabs coated with various, new antibiotics to see which ones killed this very virulent strain of TB. We wore full body, disposable coveralls, full face mask, gloves, booties, etc... - that virus was really nasty.
Our pipets were precision, glass tubes that accurately measured microscopic amounts of the virus in solution. They cost a bundle, and normally, they were washed, then steam sterilized. About half of them usually ended up broken just from the sterilization process. I made the big mistake of adding a capfull of Clorox Bleach to the washer, which was less than an ounce. The pipet washer ran all night long, probably a couple hundred gallons of water went through them, then then next day they were steam sterilized and dried for use.
We thought we had discovered the miracle antibiotic - one that killed the TB instantly. Each day, when we pipetted the TB into the petri dishes it died - instantly. After a week, we got a new shipment of pipets in the lab, went to work, and damned if the TB didn't grow just like it always did. It didn't take long to narrow down the reason the virus died. It was the residual chlorine in the pipets.
Now, if anyone out there knows of any form of bacteria that is resistant to chlorine, please feel free to post the information. I, for one, would really like to know about it.