The increased damage was shown in the stats pane. The increases were small--only a few points of dmg so I really couldn't say if I killed any faster with the strength bonus, and to be honest I usually didn't pay much attention to the brief on screen flashes which show the damage. So the short answer to your question of whether I am sure I actually got the bonus is that I don't know. My post was a reflection of having seen the dmg boost in the stats pane.

The question is not, Can they reason? nor, Can they talk? but, Can they suffer?
~Jeremy Bentham