none whatsoever.

I am generally not a fan of teas as testing done with them has yielded, at best, mixed results. They aren't harmful, they just seem to have little benefit on anything other than soils mostly devoid of any other organic matter where anything organic will help.

However, since you will have it as a byproduct, of course it should be put to some use. I doubt there will be any positive effect on your garlic from using it at this point, but I also can't think of any reason why it would be in the least bit detrimental.