I'll go and ask it now. I think it makes sense to stack because bunkers make units harder to hit, by one die. And the wolverine makes units harder to hit by one die. They feel like two independent buffs to me.
I'll summarize the thread once we get an answer!
Hmmm. Unless there has been some clarification somewhere, I would not agree. For example, stacking the Movement special ability does not make sense.
Page 13 says "A unit with a buff, any any units in the same grid as that unit, always have that buff." Maybe I am reading too much into it, but "that buff" means "Bolster -1". So the units would have "Bolster -1" twice, not "Bolster -2".
Something to ask on the CMON forum probably.
If you have a reference, I would appreciate knowing myself.