In a large saucepan, cook broccoli in 6 cups boiling water for 2 minutes. Drain and immediately rinse in cold water. In the same saucepan, cook tortellini according to package directions. Drain and immediately rinse in cold water.
In a large bowl, combine the red onion, raisins, broccoli and tortellini. Combine the mayonnaise, sugar and vinegar. Pour over tortellini mixture; toss to coat. Refrigerate for at least 1 hour. Just before serving, stir in bacon and sunflower kernels.