I've kept many anthias species for years, including lyretails, and two feedings a day has been sufficient for these. One feeding a day will not be enough, and I've seen this species grow thin as a result of one feeding. Two feedings a day will do all fish well, but many planktivorous species like anthias require more frequent feedings...
Also, when you first attain the fish, you may want to feed even more frequently for a few weeks to make up for lost body fat as a result of no feeding through the transportation process...