Cook pasta according to package directions until tender but still firm to the bite. Drain and rinse under cold water 30 seconds. Whisk together mayo, yogurt, and vinegar in a small bowl. Season to taste with salt and pepper. Place tuna in a large mixing bowl and break up. Add pasta, celery, tomatoes, peas, and onion and stir to combine. Add dressing and stir to combine. Refrigerate until ready to serve.