My pup Sophie use to throw up sometimes after eating, or spit up undigested food, foam, her water, on top of snoring worse than my grandmother ever did. She needed her soft palate lasered as it was too long (common in this breed) and she was great after that (though I am the one whose pup got osteomyelitis in her tail bone as the breeder docked her tail but did not tell me). Anyways, our vet actually mentioned signs similiar to the one you mentioned and what we experienced and said that when he spayed her he would measure her palate and do the procedure. He came from the Univ. of GA whose mascot is bulldogs and was very knowledgeable about this. It worked!

Good luck!
Michelle