Thread 6 scallops onto each skewer. Cover and chill. Preheat broiler. Cut peppers in half lengthwise, discard seeds and membranes. Place pepper halves, skin side up, on a foil-lined baking sheet, flatten with hand. Broil 15 minutes or until blackened. Place in a zip-top plastic bag. Seal and let stand 10 minutes. Peel peppers and discard skins.
Place peppers, wine and broth in a blender, process until smooth. Combine pepper mixture and basil in a skillet. Bring to a boil, cook until reduced to 1 1/2 cups (about 5 minutes). Reduce heat to medium low, gradually add butter, stirring until melted. Cover and keep warm.
Grill scallops 2 1/2 minutes per side on greased grill. Serve with pepper sauce and fresh basil.