Soak wood chips in water 1 hour; drain well.
Combine salt, pepper, and garlic powder; sprinkle evenly over steak. Let stand at room temperature 30 minutes.
Remove grill rack; set aside. Prepare grill, heating one side to high and one side to medium. Place wood chips on hot coals on medium-heat side of grill; heat wood chips 10 minutes. Coat grill rack with cooking spray; place on grill.
Lightly coat steak with cooking spray. Place steak on grill rack over high-heat side of grill; grill 6 minutes, turning 3 times. Place steak on grill rack over medium-heat side of grill; grill 40 minutes or until a thermometer registers 140° (medium-rare) or until desired degree of doneness. Remove steak from grill; let stand 10 minutes. Cut steak diagonally across grain into thin slices. Serve with Santa Maria Salsa; garnish with cilantro sprigs, if desired.
Wine note: Tri-tip from California's Santa Ynez Valley goes naturally with a full-throttle merlot from the same region. Gainey Merlot 2004 (Santa Ynez Valley, California), $26, is plush and plummy, with enough structure to stand up to the steak, the char-smokiness of the wood chips, and the pungency of the salsa. --Karen MacNeil