Grease grill rack, preheat grill to medium-high heat for direct cooking.

For pineapple slaw, in a medium bowl, combine coleslaw mix, pineapple, red pepper, onion, yogurt, 1/4 teaspoon salt and 1/4 teaspoon sriracha sauce; set aside.

In a medium bowl, combine olive oil, chili powder, and remaining 1/2 teaspoon salt; dip both sides of each fish fillet in oil mixture to coat. Place fish skin-sides down on grill rack. Grill, covered, without turning for 6 to 8 minutes or until fish flakes easily with a fork. Transfer to a plate; keep warm.

Grill tortillas about 20 seconds per side or until warm and slightly grill-marked. Break fish into bite size pieces; sprinkle with remaining 2 teaspoons sriracha sauce and squeeze juice from two lemon wedges over fish. Divide fish and slaw among tortillas. Serve with remaining lemon wedges for squeezing over tacos.