In a blender, combine 1/4 cup extra virgin olive oil, 1/4 cup white wine vinegar, cilantro leaves, lime juice, and salt and pepper taste. Blend until smooth and emulsified. Set aside.
Cut heads of romaine lettuce in half lengthwise through the root end. Keep root attached for easier grilling. Brush cut sides of lettuce and ears of corn with remaining olive oil. Season with salt and pepper. Grill lettuce and corn on medium-low heat for 3-5 minutes flipping once or until lettuce is slightly charred and wilted but not soggy and corn is tender. Remove from the grill. Cut kernels from cobs.
Arrange grilled lettuce on four plates and divide grilled corn and tomatoes amongst the salads. Drizzle with dressing and serve immediately.