In a large bowl, combine the chopped romaine lettuce, cherry tomatoes, cucumber, red onion, bell pepper, Kalamata olives, mozzarella balls, and fresh basil. Toss gently to mix the ingredients evenly.
In a separate small bowl, whisk together the red wine vinegar, olive oil, dried oregano, garlic powder, salt, and pepper until well combined.
Pour the dressing over the salad and toss again to ensure all the ingredients are coated.
Let the salad sit for about 10 minutes to allow the flavors to meld.
Serve immediately or refrigerate for up to 1 hour before serving for a chilled option.