Cook the rotini pasta in a large pot of salted boiling water for 8-10 minutes or until al dente. Drain and rinse under cold water.

In a mixing bowl, combine the red onion, cherry tomatoes, cucumber, black and green olives, and bell pepper. Toss gently to mix.

In a small bowl, whisk together the Italian dressing, mayonnaise, and red wine vinegar until smooth. Adjust seasoning if needed.

Pour the dressing over the vegetables and add the cooled rotini pasta. Toss everything together until evenly coated.

Fold in the mozzarella and parmesan cheese. Season with salt and pepper, mixing well.

Cover the salad and chill in the refrigerator for at least 30 minutes before serving.