I had a similar issue when Eeees and I went to St. Thomas. We went to the local supermarket and were surprised to find that the Coca-Cola in St. Thomas did not have a hechsher. I figured it was simply a lack of a mashgiach at the plant and not that it was truly not kosher.
In the end, we didn’t buy it, simply because Coca Cola isn’t all that important to us and kashrus is. But if I had to bet money on it, I would have given given dollars to donughts that it was, in fact, kosher. They don’t make special treif Coke just for the Virgin Islands.
The Wolf