In large nonmetal dish or resealable food-storage plastic bag, place chicken and 3/4 cup chipotle marinade; turn to coat. Cover dish or seal bag; refrigerate at least 20 minutes or up to 2 hours to marinate.
Heat gas or charcoal grill. Remove chicken from marinade; discard marinade. Place chicken on grill over medium heat. Cover grill; cook 10 to 12 minutes, turning halfway through grilling, until chicken is fork-tender and juice is clear when center of thickest part is cut (170°F). Let stand 5 minutes; cut into 1/2-inch strips.
In small bowl, stir together salsa, cilantro, 2 tablespoons chipotle marinade, the oil, lime peel and lime juice. In large bowl, toss lettuce, corn, bell pepper and beans; toss with salsa mixture.
Divide bean mixture among 4 serving plates. Top each with chicken. If desired, serve with sour cream.