Coat a Dutch oven with cooking spray; place over medium-high heat until hot. Add tomato and next 4 ingredients; saute 6 minutes or until onion is tender. Stir in chicken and next 7 ingredients. Bring to a boil; cover, reduce heat, and simmer 20 minutes. Stir in bulgur; cook 15 minutes or until bulgur is tender.
To serve, ladle soup into individual bowls, and top each serving with 1 tablespoon yogurt.