Put wine, onion and garlic into medium saucepan. Bring to a boil over medium-high heat and reduce until about 2 tablespoons of liquid is remaining. Pour reduced wine mixture into shallow pie plate and let cool to room temperature.
Meanwhile, in large mixing bowl, place ground chicken meat, salt, pepper, mustard, spinach, grated Swiss, bread crumbs and cooled wine mixture. Gently combine (do not over mix!) and form into 6 patties.
If using gas grill, preheat to high. Brush the grids with olive oil, turn to medium heat and place patties on grill. Close lid and grill for 10 minutes. Flip burgers over, close lid, cook for about 6 more minutes. Brush both sides of rolls with olive oil, place on grill, place 1 slice Swiss on each burger and close lid for about 30 seconds. Check rolls and remove when golden brown. Remove burgers as soon as cheese melts a little. Place patties on rolls, top with tomato slices and serve.
You can also make these inside the house. Preheat large frying pan over medium heat. Add enough olive oil to coat bottom of pan and heat. Add the patties and cover pan for 10 minutes. Flip burgers over, cover pan and cook for about 6 to 8 minutes more or until juices run clear. Top with Swiss and replace cover until cheese melts. Buns can be browned under the broiler.