A good rule of thumb is to start with an amount of bicarbonate solution equivalent to the volume of the reaction mixture and check how it goes. When doing lab-scale experiments relatively little can go wrong, though frothing may occur when a large amount of HBr is present.
I've got another concern, though, and that is that you don't seem to neutralize any excess bromine first. All my brominations were followed by washing with bisulfite or dithionite before any other workup.