Brush corn and steaks with 1 tablespoon olive oil; preheat grill to high heat.
Grill corn 10–12 minutes, turning often; grill steaks 5 minutes per side (145°F internal temperature), then rest 3 minutes.
While meat grills, whisk together butter, minced garlic, chopped basil, 2 tablespoons olive oil, and red wine vinegar.
Halve cherry tomatoes, toss with herb-garlic oil, divide among plates with corn and sliced steak, and serve.