Pillar bedding means it is glass bedded, but, also where the action screws run through the stock there is a steel or alluminum pillar that the action rests upon for a non compressable surface to torque the action screws down onto.
I've tried several different bedding materials over the years and I probably use Marine Tex more than any other. Devcon steel or alluminum putty works just as well but is more expensive. I can get the Marine Tex in a small kit for about $12 and it is the perfect amount to bed a Remington style action with.
I wouldn't waste your time trying to pillar bed or even full action bed a synthetic stock. The tupperware stocks aren't worth the cost to even practice with. There is too much oil in the plastic of those stocks and it's a real bitch trying to make the bedding stick. I prefer to pillar bed all of my rifles rather than just full action bed them, but some kind of bedding is better than none. Good luck.