In large nonmetal dish or resealable food-storage plastic bag, mix all steak ingredients except steak. Add steak; turn to coat. Cover dish or seal bag; refrigerate at least 4 hours or overnight to marinate.
Heat gas or charcoal grill. Remove steak from marinade; discard marinade. Place steak on grill. Cover grill; cook over medium heat 10 to 15 minutes, turning once or twice, until of desired doneness.
Cut steak across grain into slices; place on serving platter. Arrange tomatoes around steak. Sprinkle tomatoes with 1/8 teaspoon pepper and 1/4 cup basil; drizzle with 2 tablespoons oil.