COOK and stir shrimp and scallops in 1 Tbsp. hot oil in large nonstick saucepan on medium heat 4 to 5 min. or until shrimp turn pink and scallops are opaque. Remove from pan; cover to keep warm. Heat remaining oil in saucepan. Add onions and garlic; cook and stir 4 to 5 min. or until onions are crisp-tender.
STIR in tomatoes, wine and crushed pepper. Bring to boil; simmer on medium-low heat 10 min.
ADD shrimp mixture, basil and half the marjoram; cook 5 min., stirring occasionally. Serve topped with cheese and remaining marjoram.