When I first bonded my pair, I also had a similar problem. I scatter feed in an upturned stove cover, which works for my rabbits. Even the sound of pellets still makes Thor chase Crysta away outside the pen, so I have to feed inside the pen, and then I don’t have issues. I would separate them during feeding times, as suggested. At the moment, I am feeding greens separately due to Crysta having some issues with gut movement (as well as CC). Thor will eat all the greens so fast, I couldn’t take any chances. Crysta can leave it or take it with greens, but it’s very important she gets back to normal (and like your dwarf, she is the smaller one). Crysta has also learnt to fight for her place as she has matured (not physically, but just standing up for herself, similar to Stickerbunny’s rabbits), so it may simply be an issue of time, even though your girl is older. Perhaps it is also a confidence thing…
With treats, I would break them up into smaller pieces for Willow, in particular, and continue to feed them at the same time. This way, Willow can eat her treat with one mouthful, preventing Julius from finishing it off. I do this with the papaya treats, and I will often break one piece up into multiple pieces so I don’t overfeed treats.