Am I eligible for a bonus for enlisting as prior service into a different branch?

It's highly doubtful. When I came back in January the Career Counselor at MEPS all but laughed when I asked about a bonus even though I signed for a critical shortage MOS.

It all depends. When I switched over in 2008 they had prior service bonus which I received 20k for. For the reserves the only bonus I know that has been constant throughout the years is joining the Drill Sgt unit and the bonus usually varies depending on the time of year from 7k to 15k.

I did the same thing, but I went active. I was told that the bonus is the chance to go back active duty. So, I wouldn’t hold my breath for a bonus man tbh

You can negotiate the terms of your contact. I had a 92Y supply clerk contact in 2003. I was offered $50K from a college fund and the recruiter said I would get an extra 3K cash bonus if I went airborne. You can ask about things like airborne, air assault, etc. Being added in for bonuses. Not sure what your tier is. I was a tier 1 recruit so I got lots of bonus money offered.