So far, skill mastery is added to these management skills: Herbalist, Stylist and Beauty GuruIn Alicia Online, if you master any of these management skills - Herbalist, Stylist and Beauty Guru - you'll gain something extra in return.
If you mastered the Herbalist skill, there is a chance that your horse's luck will increase when you feed it. However, if your mastery is in Beauty Guru, there's a chance of increasing your horse's luck when you groom it. The chances of getting that luck increase depends on the skill rank of your Herbalist and Stylist skill.
Having a Stylist mastery will not grant you extra luck but it'll make your horse look so much nicer. If you clean the same part on your horse (parts include the body, mane and tail) for more than 10 times, this part will become sparkly and shiny. Naturally, a higher Stylist skill will make your horse's coat shinier.