If you get an Enlistment Bonus for an National Guard MOS then Commission Through ROTC or State OCS, do you have to payback your bonus?

It depends on the conditions of your bonus. I wouldn’t worry about that to much either way. In the long term commissioned service will probably make up financially whatever you might lose in the bonus.

depends on how your contract is worded. I got an enlistment bonus when I got back in the guard with half paid up front and the 2nd half paid after 3 years. I got commissioned 2 weeks shy of the 3 year mark. I just didn't get the 2nd half of the bonus. Did not have to pay back the first half.

You need to read your contract. If you do not meet the requirements for your enlistment contract bonus, the government will take it back. Of course, you are going to still be serving, so you may not. It really depends. You need to talk to your HRA and your unit.