Thanks for sharing your experience with your English Bulldog. She just started this when she turned 5. The sweet retriever goes home tomorrow and since she lives a couple hundred miles from us, I don't think I will have her again. Like your retriever she would always win the fight. She would get a little slobber on her but the Bully would always get the worse of it. When they do get in a fight I always have a harness on the Bully so I can just grap it and get it broken up before any real damage can happen. Since she was a year old I would take her & 4 other dogs to our Dog park. She loved playing with all the dogs & she thought every one should have to say hi and give her some loves. Not once did she ever get in to a fight. Then when she was 3 years old, the other dogs moved away so we don't go to dog park very often but I have a big yard for her to play & run with the other dogs that stay overnight. She never has any problem with dogs smaller than her, in fact her best friends are a doxie(female) and a male Bichon/poodle mix. They could play for hours.
So you may be right about jealousy, but I try to give lots of love to her and things should be back to normal after tomorrow I hope. Will let you know How it goes.