For tahini yogurt: Combine lemon juice, Baharat Seasoning, and garlic in medium bowl; stir to blend. Let stand 5 minutes. Whisk in yogurt and tahini. Season tahini yogurt to taste with salt. DO AHEAD: Can be made up to 2 hours ahead. Let stand at room temperature.
For pomegranate relish: Mix all ingredients in medium bowl. Season to taste with salt and freshly ground black pepper. DO AHEAD: Can be made 2 hours ahead. Let stand at room temperature.
For chicken: Whisk first 4 ingredients in large bowl. Add chicken. Sprinkle with salt and pepper. Marinate at room temperature at least 1 hour and up to 2 hours.
Preheat broiler. Thread 6 chicken pieces onto each skewer. Sprinkle with salt and pepper. Place on small rimmed baking sheet. Broil chicken until cooked through, 5 to 6 minutes per side. Arrange kebabs on platter. Serve with tahini yogurt, pomegranate relish, and warm pita breads.