1. Bring a large saucepan of salted water to a boil. While the water heats, in a large skillet over medium heat, cook the bacon until it is crisp, 6 to 7 minutes. Add the scallions and tomatoes, then sauté for 2 minutes. Use a slotted spoon to transfer the mixture to a bowl, draining any excess fat.
2. Cook the pasta according to package directions. Reserve 1⁄4 cup of the cooking water, then drain the pasta and return it to the saucepan.
3. Add the cream cheese and half of the reserved cooking water to the pasta. Toss until the cheese is melted and forms a creamy sauce.
4. Add three-quarters of the bacon and tomato mixture, then toss again. If the sauce is too thick, add a bit more of the reserved cooking water. Taste and season with salt and pepper. Divide the pasta among 4 plates, then top each serving with some of the remaining bacon and tomato mixture.