Yes the tune (I.E 87, 91, 93) is the minimum octane rating that you should run when running that tune. You need to run 87 octane (reg) with the 87 tune, 91 octane or greater (mid-grade) with the 91 tune and 93 octane ore greater with the 83 tune.
Top center under support, click on forum. Don't expect very clear answers though, I have found that most of the answers you get are very vague. I get the impression (from searching and reading through the site) that the company consists of only a few people opperating out of a garage.
One programmer, and two customer service reps/salesmen/forum mods. Im sure it's not that way, but that is the impression I get from them.