Since it sounds as though nothing has been filed, then you would not be in violation of anything from the court's perspective if you gifted the bonus; but by gifting the bonus, I am not sure what you think you are accomplishing by gifting the money.
A bonus is income and treated no differently than regular earnings, so when you get divorced and complete the mandatory court financial form, the bonus income must be reported. If you gift it out, it will not be as though the money did not exist - you just won't have it.
If you are worried that your spouse will access the funds, then you could put the bonus money in a separate account. Your spouse should probably not have taken all of your joint funds when you separated, and you should account for this and make an adjustment as part of your property division, which must be equitable - although not necessarily equal in MA.
Finally, keep in mind that when the divorce is filed, both parties will be subject to an automatic financial restraining order.
I hope that helps. It is difficult to give specific advice without obtaining more detailed info. Sounds like you should meet with someone for a consult and do some pre-divorce planning. Good luck with your case.
Steve McDonough, Esq.