Are there any pictures that show the back of the belt in any way?
While leather-grade contact cement like Barge can yield a very strong permanent bond, I don't think it would be sufficient in this case. There's very little surface area for the cement to bond with and a grain-to-grain connection is much less reliable compared to flesh-to-flesh (backside of the leather).
Considering the tensions on those pouches I would guess that cement alone is not enough to keep them in place. It would be fairly simple (and common practice) to reinforce the glue bonds with a couple short rows of stitching. I think that would give the desired visual result and also make sure the pouches don't fall off.
And @
Crazylegsmurphy, the way you have the canister pouch pictured would be perfect for just running a quick line of glue to hold it in place and then hand-stitch down each side to permanently secure.