Spanish is useful in most places, and extremely useful, I think, in places like Texas, California, and New York. But it's not required for most US schools, and 2 years of a language, in any case, probably won't help your chances that much, unless you can become pretty fluent or demonstrate real competence in that language.
Surprisingly, I've been told that the hospital of the University of Pennsylvania doesn't need Spanish speakers - I don't think that they even have a Spanish translator on staff in the ER. They have a lot of African immigrants in West Philadelphia, so they're always on the lookout for French translators, though.