Well first up dude, that workout doesn't only have 2 sets on the chest. If you think about the movement being trained (push, pull etc) you see that including dips, there has 6 sets + the pressing portion of the clean and press. Every movement done involves the pecs, shoulders and triceps to some degree.
For chest alone I'd say 6 sets would be plenty when following a full bodyish program as long as you control the weights descent fully on every rep. No jerky reps! By full bodyish I mean a program in which you work legs every workout.
I reckon maybe you're chest is behind the rest of your body could be because you're working really hard on it. Do you find your other workouts can lag, but your chest workouts are always good? This could mean you're overdoing it. You only need to give it the same consideration as your other body parts and in conjunction with them it will grow.
But it's really hard to say as I can't see you or talk to you in person. I think it's best to concentrate on strength increases, size always comes with strength, so the program that's the best is the one you can increase the numbers every set, every workout. Not as easy as it sounds after 4 workouts and you've found your limits!
Hope that helps.