In a skillet over medium heat, cook the bacon until crispy, about 6-8 minutes. Once done, transfer to a paper towel-lined plate to drain excess grease, then chop into bite-sized pieces.

Bring a large pot of salted water to a rolling boil and add the frozen cheese tortellini. Cook according to package instructions, around 3-5 minutes, until al dente. Drain and rinse under cold water.

In a large mixing bowl, whisk together the mayonnaise, red wine vinegar, salt, oregano, Italian seasoning, garlic powder, and red pepper flakes until well combined.

Add the cooled tortellini, chopped bacon, pepperoncini, Parmesan cheese, sliced red onion, and fresh tomatoes to the bowl with the dressing. Gently toss until all ingredients are evenly coated.

Cover the bowl with plastic wrap and refrigerate for at least 2 hours.

Before serving, give the salad a stir to redistribute the dressing and enjoy it cold or at room temperature.