Place the oven rack in middle position and preheat oven to 400°F. Line 2 large baking sheets with parchment paper.
In a large bowl, whisk together flour, baking powder, salt and baking soda. Add zucchini, ½ cup tomato, scallions, basil and cheese; toss to combine.
In a medium bowl, whisk together buttermilk, eggs, oil and vinegar. Pour buttermilk mixture into the dry ingredients. Stir just until blended; batter will be thick.
Drop dough by 1/4 cup mounds about 2 inches apart on baking sheet. Garnish with fresh tomato slices. Bake until golden brown, 25-35 minutes and toothpick inserted into the center of biscuit comes out clean. Transfer to a wire rack and cool about 10 minutes before serving.