I agree. Columbus's first landing in OTL was in the Bahamas, too, and it didn't have much effect. He found Cuba 2 weeks later, and Hispanola a week after that. I suppose you could have an interesting divergence if landing in Eleuthra (which is NW of San Salvador) caused him to head for Florida instead of Cuba. Maybe the Floridians would be better equipped to withstand Spanish forces. Even then, though, you'd have to have something pretty unfavorable happen on that first voyage for it not to lead pretty quickly to a TL that's indistinguishable from our own (minus butterflies, of course).