Cut pork loin crosswise into eight pieces. Sprinkle lightly with salt and pepper. Wrap one slice of bacon around each piece of pork; secure with a small skewer or wooden pick. For a charcoal grill, arrange medium-hot coals around a drip pan. Test for medium heat above pan. Place pork on grill rack over pan. Cover and grill for 25 minutes or until pork is slightly pink in center and juices run clear (160 degrees F), turning once halfway through grilling.
Meanwhile, chop four of the green onions; set aside. Place remaining onions on grill rack over coals. Grill for 3 to 4 minutes, turning occasionally until just tender.
In a saucepan combine the chopped onions, tomatoes, beans, ketchup, the water, and mustard. Bring to a boiling; reduce heat. Cover and simmer until pork is done. Serve with pork and green onions.