Is 2 years of a foreign language enough to be competitive with most liberal arts colleges?
Language requirements vary from one school to the next, and often from one program to the next. The only way you’re going to know for sure is to investigate specific opportunities. As an aside, as we become more of a multi-cultural society, the ability to converse in multiple languages is a plus. It will help you, perhaps, more in your career than in your college education. If Spanish is something that you’re doing well in, you might consider another year for reasons beyond college admissions.