We had this problem when we brought Jewelie into the house at Christmas time. Buckley had been with us as an only dog for almost 5 years. They had 4 or 5 real knock down drag'em outs and a few snaps here and there, especially over food or toys. Jewelie was very "alpha" at meal times, barking at me to feed her and then, when she finished before Buckley, going over to his bowl and growling at him while he ate.
I changed this (and so far so good) by feeding him first and making her sit and wait while he got a head start. Her food is down where she can see it, but she has to wait for me to release her before she can eat. Very little barking at me any more, and no more squabbles at meal times. And overall, more peace. /forums/images/%%GRAEMLIN_URL%%/smile.gif
With her, we have had to be extremely firm - especially me. Hubby has no trouble establishing dominance over the dogs, but I'm a soft touch. She was really in my face, though - not aggressive or anything, just BOSSY. So we worked on training and the sit and wait commands at meal time made a huge difference overall. She is much more mindful of me, but also adores me and follows me everywhere. Life has settled into a lovely routine, and all is well.
Oh, and lest I make it sound easy, we have been working on this since Christmas and it is still a bit of a work in progress, but MUCH better than it was!!