Hi Thomas!
I knew someone some years ago, that put together a companion list. His states that Lettuce does not have a bad companion. But that it especially loves to grow with carrot, garlic, onion, and radish.
His list is based on the concept of Integrated Pest Management.
Planting plants that attract predators that will branch out and feed on the bad bugs on your desirables.
Planting plants that will attract the bad bugs away from your desirables.
Planting plants that will attract pollinators to aid your desirables.
I don't know if this is specifically what you were looking for, but I hope it helps.
