Combine the first 4 ingredients in a zip-top heavy-duty plastic bag; seal bag, and shake well to coat. Marinate the snapper strips in refrigerator 20 minutes.
Heat tortillas according to package directions.
Heat oil in a small nonstick skillet over medium-high heat. Add sliced onion and bell pepper strips, and sauté 5 minutes or until crisp-tender. Remove skillet from heat; set aside, and keep warm.
Arrange snapper strips in a single layer on a broiler pan coated with cooking spray. Broil 8 minutes or until fish flakes easily when tested with a fork, turning after 4 minutes. Divide fish and bell pepper mixture evenly among warm tortillas, and roll up. Spoon Pineapple Salsa over fajitas.