Only with caution. Heniochus bannerfish, such as the pennant coralfish (Heniochus acuminatus), eat zooplankton but also pick at coral polyps and occasionally bottom-dwelling invertebrates, so many reef keepers do not consider them fully reef safe.
They can do well in fish-only tanks or reefs with hardier corals, but they may nibble soft corals, large-polyp stony corals, and tubeworms. The pennant coralfish can reach about 25 cm (10 inches), so it also needs a large aquarium.
Source: Wikipedia: Pennant coralfish