I've noticed that after I feed the geos and they have gotten their fill, they will start posturing to each other. Gills flared, fins erect, and they fin slap each other. They will occasionally jaw lock, but its not longer than 20-30 seconds. Any other time of the day they get along and kinda school. Why is it that after they eat they get rambunctious?

Could be they are compeating for who is top dog and the feeding just happens to trigger this off, other than that i aint got a clue as i have not had much to do with cichlids, Cichlid Commander might be able to answer this better for you next time he is on the boards

Could it be just that feeding time brings them together.

Like other other animals drawn to the watering hole. Time to posture, and sort out who get first dib's.

Only other thing i can think of is it a courtship display ? or are they too young ?

They are probably too young at 4"-5". It might be that they are just sorting out the pecking order and/or mock courting. I don't know for sure. They didn't do it last night when I fed them frozen brine and frozen bloodworms.

Maybe thats because you were watching and they have got shy Or it could be they have sorted out who is top dog