I think that Rob wins too. If we were to examine every possibility of these people going against him...
Phillip - He's pissed every single person off. He might claim to have a great speech at the end to take down Rob. But he's forgotten that actions speak louder than words. All the annoying actions he's done to the people around him, they're not gonna let that go based on a single speech.
Natalie - What's she even doing on Survivor? She's done absolutely NOTHING.
Ashley - Same as Natalie. She might have started making moves towards the end, but that's certainly not enough. She spoke of getting Rob out, why didn't she do it at the Final 5? She had the Immunity necklace, there was no way Rob could get her out, why not stir something up, plant seeds in the others' minds that they were not gonna win against Rob? If her plan failed, she'd be in trouble the next episode. Then again, she was already in trouble to begin with. Why not make the best of what she had?
Grant - Physical, check. Mental and strategic, no. The Final 5, IMO, was the best chance for Grant, Natalie and Ashley to band together to get rid of Rob. But yes, they're just too mesmerised with him to do so.
Andrea - Same as Grant, I would say.
Matt - He spent like, what, 5 days in the game and 30 days on RI or something? He's not gonna make much of an impression on the jury members. He didn't really get to play the game, he just survived on RI all the while.
I think the person who has SOME chance at beating Rob is Mike. He MIGHT get Zapatera's votes.
But to take everything into consideration, I don't see why Zapatera should hate Rob. He did not betray them, he just did what he had to do, which was keep his tribe together, make use of the numbers and vote the other tribe out. They should give him credit for that. And Ometepe doesn't hate Rob too, in fact I think they love him to death. So to think of it very rationally, I say Rob wins. Geez.