Wrap 1 bacon slice tightly around each wiener, tucking in ends of bacon slices to secure. Grill 8 to 10 min. or until bacon is done and wieners are heated through, turning occasionally.
Drain on paper towels. Meanwhile, brush mayo evenly onto both sides of buns, then grill 1 to 2 min. on each side or until lightly toasted on both sides.
Fill buns with wieners; top with tomato mixture, ketchup and mustard.