Take the bonus and hold on to it. If you make it two years, pocket it. If you don't, pay it back. Don't let a regional get away with two years of your time without coughing up the dough.
As far as the majors go, there are thousands of guys who aren't getting looks from the majors, guys who have similar hours to yours, or more, but their turbine time is in multi-engine transport category jets, not in a light single-engine turboprop that doesn't require at type.
If you have a shot at the majors, it won't be because of your flight experience. It will be because of the other factors that go into their algorithms, and the intangibles.