Probably not much to go on, but I received a $10 sports bar food comp for around 2-3 hour of 3-6 or 4-8 HE at the IP. I think their official rate is $1 per hour, but it depends on if you are nice or not. VP comps seem to go a long way in Biloxi, plus there are numerous great non casino local places to eat, so you may want to approach rooms and food through VP.
I think, but could be wrong, that the general standard is $1 an hour, but as with all things Mississippi....Niceness counts.