For those of you that wish to correct me if I'm wrong feel free. However, all the literature I have seen on growing big bluegills is to have a large bass population and to release the large male bluegills. That means you will have lots of skinny undersize bass unless you feed some like I do. The bass heavy population keeps the bluegill numbers down and promotes more food to go around. This is for huge bluegills. You can still have big bluegills if you have a balanced population.
I have two kinds of bass in my pond. Feed trained bass up to about 5 pounds that I feed daily, and are built like tanks (tiger tanks as in tiger bass,) and a population of skinnier bass that were spawned in the pond and were not trained on pellets. I have very few bluegills, but what I do have looks like it is on steriods. I mentioned one on this site I released last year that was only 9 inches but weighed 14 ounces.