Coat a large nonstick skillet with cooking spray; place over medium-high heat until hot. Add chopped pepper and garlic; saute 2 minutes. Add spaghetti sauce and 1/2 cup water. Bring to a boil; reduce heat, and simmer, uncovered, 10 minutes, stirring occasionally. Set aside, and keep warm.
Combine cheeses and pesto in a small bowl. Place 1 wonton wrapper on a work surface. Place a second wrapper (at a one-quarter turn) on top of first wrapper, creating a star design. Place 1 tablespoon cheese mixture in center of star. Moisten edges of wrappers with water; fold in half, bringing edges together. Press firmly. Repeat procedure with remaining wrappers and cheese mixture.
Bring 2 quarts water to a boil in a large saucepan over high heat. Add half of wontons; boil, uncovered, 1 minute. Remove from water, using a slotted spoon; set aside, and keep warm. Repeat procedure with remaining wontons. To serve, spoon one-fourth of spaghetti sauce mixture onto each plate. Top each serving with 3 wontons. Serve immediately.