Obviously the bonus feats from fighter and monk stack w each other, despite being the same name.
do they stack w those of the brawler, despite having the same name and being parent classes?
there is no stacking issue.
The ACG mentions that class abilities of the same name do not stack Between hybrid and parent classes.
Bonus feats stack in the sense that you get more and more, not exactly like sneak attack stacking but kind of similar.
BBT is correct.
In fact, when combining the fighter there IS a stacking issue but not a big one:
At 1st level, and at every even level thereafter, a fighter gains a bonus feat in addition to those gained from normal advancement (meaning that the fighter gains a feat at every level). These bonus feats must be selected from those listed as Combat Feats, sometimes also called “fighter bonus feats.”
Upon reaching 4th level, and every four levels thereafter (8th, 12th, and so on), a fighter can choose to learn a new bonus feat in place of a bonus feat he has already learned. In effect, the fighter loses the bonus feat in exchange for the new one. The old feat cannot be one that was used as a prerequisite for another feat, prestige class, or other ability. A fighter can only change one feat at any given level and must choose whether or not to swap the feat at the time he gains a new bonus feat for the level.
For the second part, the one about replacing bonus feats, there is a stacking issue and they only stack if specifically called out to stack.
So a level 2 fighter/ level 2 brawler would get 3 bonus feats (F1, F2, B2) but would not be able to swap out a bonus feat as fighter and brawler do not state to stack for bonus feat swapping.
thanks everyone for the imput