Set up the grill for direct cooking over medium heat and oil the grates.
Place halibut on a plate and rub with taco seasoning. Cover with plastic wrap and cure in the refrigerator for 30 minutes.
Place the halibut on the grill and cover. Cook for 4 minutes per side, or until the fish flakes easily with a fork. Remove from the grill and let stand 10 minutes.
Meanwhile, in a medium bowl, combine salsa, peaches, and allspice.
Cut the halibut into bite-size pieces. Place halibut pieces in warmed tortillas and top with salsa and coleslaw mix. Serve warm.