I would definitely cut out the alfalfa hay completely, it's not good for fully grown, healthy bunnies, is hugely fattening (much more so than readigrass) but just as importantly it's extremely high in calcium. Coupled with other calcium rich foods like carrot tops, they will be at enormously increased risk of developing kidney/bladder stones, as bunnies excrete excess calcium through their bladders.
It looks to me as if the diet you're giving is generally pretty good, hopefully it should only need a bit of tweaking of quantities and cut out alfalfa and sugary treats and hopefully their weights will remain stable. Good luck x