In a large skillet over medium heat, cook the bacon until crispy, about 6-8 minutes. Transfer to a paper towel-lined plate to drain and chop into bite-sized pieces.

Bring a large pot of salted water to a rolling boil. Add the frozen cheese tortellini and cook according to the package instructions, about 3-5 minutes. Drain and rinse under cold water.

In a mixing bowl, combine mayonnaise, red wine vinegar, garlic powder, oregano, Italian seasoning, and red pepper flakes. Whisk until smooth.

In a large bowl, combine cooled tortellini, chopped bacon, pepperoncini, diced red onion, sliced tomatoes, and grated Parmesan cheese. Drizzle dressing over top and fold together until evenly coated.

Cover the bowl and refrigerate for at least 2 hours to allow flavors to meld.

Before serving, stir gently and serve cold or at room temperature.