Cook pasta according to package directions; drain well.
Cut bell pepper into 1-inch-wide strips. Cut off ends of zucchini and yellow squash; cut each lengthwise into 4 equal slices. Cut onion into 3/4-inch-thick rounds.
Grill bell pepper, zucchini, yellow squash, and onion, covered with grill lid, over medium-high heat (350° to 400°) 4 to 6 minutes on each side until tender. Let stand 10 minutes, and coarsely chop.
Place pasta in a large bowl, and stir in grilled vegetables, tomatoes, and cheese.
Whisk together red wine vinegar and remaining ingredients; add to pasta mixture, tossing to coat. Cover and chill at least 2 hours or up to 6 hours.