Place the Alfredo sauce, cream cheese, spinach, red bell pepper, red onion, mozzarella cheese, and Romano cheese into a blender. Cover the blender and blend until well-mixed.
Pour dip into a baking dish; sprinkle the Cheddar cheese on top.
Bake in the preheated oven until bubbly and the cheese is melted, about 30 minutes. The dip will be runny but will thicken as it cools.
Meanwhile, arrange the pita wedges on a baking sheet.
Drizzle with vegetable oil, and season with salt.
Bake in the preheated oven until pita wedges are toasted, about 10 minutes. Serve with dip.
