Place potatoes in a medium saucepan; cover with water, and bring to a boil. Reduce heat, and simmer 10 minutes or until tender; drain.
Combine potatoes and next 11 ingredients (potatoes through garlic) in a large heavy-duty zip-top plastic bag. Seal bag, and marinate 30 minutes, turning bag occasionally.
Remove vegetables from bag, reserving marinade. Place vegetables in a wire grilling basket coated with cooking spray. Prepare grill. Place grilling basket on grill rack, and grill 7 1/2 minutes on each side or until tender. Place reserved marinade in a small saucepan; cook over medium heat 3 minutes. Pour warm marinade over grilled vegetables.