Here's a generic answer: as long as you're happy and you get your job at the end of the school year, it doesn't matter if you went to Harvard or to University of Phoenix.
Your question is a bit broad to answer and a lot will depend on what you're looking for after your MBA and your desire of getting an MBA. If you're looking to get into Goldman Sachs, no, non-top tier schools will simply make it almost impossible. If you'd like to work for a small, regional place that recruits from the regional MBA school you're thinking about, you'll be fine.
Find out what's new at GMAT Club - latest features and updates