Here's my spin.
Game Fish Chow should not cost $25 per bag. You are overpaying. You can get AquaMax for $25 per bag and it's a better deal for bluegill, anyway.
Since you are de-emphasizing the 4 acre pond, leave the vegetation alone (unless it's all algae, which I doubt). Since your mission is to grow larger bass and the food chain had been depleted, heavy mats of vegetation, for the next two years, is your friend, unless it covers more than 30% of your pond's floor. Heavy vegetation is great cover for small fish. So, in your case, mats of plants could be the stimulus package to bring your bluegill out of bankruptcy into an honest-to-gosh food chain. Essentially, right now the heavy mats of plants are habitat, not a nuisance. It becomes a nuisance if there's too much coverage or your lake is otherwise balanced and ready for fishing.
While tilapia would definitely be an added benefit, if you must choose, I would choose feeding.
