Place zucchini, tomatoes, and sweet pepper in a large resealable plastic bag set in a shallow dish. Add pesto and vinegar; seal bag. Knead bag to coat vegetables. Marinate at room temperature for 30 minutes.
Meanwhile, remove leaves from all but 2 inches of the rosemary sprigs (if using). Wrap bocconcini in salami or prosciutto strips. Thread 1 wrapped cheese piece onto each of the rosemary skewers, inserting the end without leaves. (If necessary, use a wooden or metal skewer to poke holes in cheese pieces before threading.)
Remove vegetables from marinade, reserving marinade. Thread each skewer with one piece of each marinated vegetable and a basil leaf, threading basil leaf around vegetables accordian-style. Arrange skewers in a serving dish. Drizzle with reserved marinade. Serve immediately or cover and refrigerate for up to 8 hours. Serve with lemon wedges to squeeze over kabobs. Makes 12 appetizer servings.