Another important thing is protein. Pollen is loaded with protein, and a lot of insects eat it. Bees clean it off their pollen thingies and eat it. They also say that's one of the benefits of eating flowers in survival situations. Protein means nitrogen. Since CPs have an ability of absorption which other plants don't, I imagine being able to "eat" pollen just like N. ampullaria "eats" leaf debris would give a competitive advantage. However, we'd need to know if CP enzymes/bacterial action could break the pollen down. Pollen would break down on the ground by bacterial action, too, but that process seems like it'd take longer to release nitrogen to weeds and other "normal" plants because it isn't right directly on the plant. CPs might likely get to it first.
I imagine that in large amounts it would make a nutritional difference. Probably not a whole lot, but a nice benefit to having constantly open pitchers and mucus glands (I imagine Drosera would be the best at catching pollen because they've got more surface area to collect on and are sticky). We could even add an experiment where we use a set amount of pollen and figure out some way to expose each kind of plant to it (i.e. a glass box with a fan or something), and then measure how much pollen falls to the ground rather than remains stuck on the plant. But pine pollen in particular I wouldn't see as being much different from any other wind-carried pollen. I also don't know, tree for tree, what species of tree produces the most pollen. In that case something producing more pollen might benefit CPs more than other trees.
And like JLAP said, in the southeast pollen typically doesn't get to sit on CPs too long before rain washes it off, and I'm not sure it'd make a noticeable photosynthetic difference.