Coming from a machinist/knife maker, not a bowyer, so take it for what it's worth, but the names phenolic & micarta are pretty much interchangeable."Phenolic" is a type of resin that can be used in the process.
In my experience most of the "Micarta" you see available is paper, canvas, or linen. Whereas most materials branded "Phenolic" I see are fiberglass.
Honestly I couldnt say which is stronger, lighter, ect. Most of the weight will come from the resins, so I would expect them to be pretty similar. Strength wise, probably the same story, but I'd take canvas or fiberglass over paper for aesthetic reasons.