Sabia mentions something about her mother using it during parties or whatever. I think it's just really good booze. I don't think you can even craft it. At least I didn't get the option. And I had all the ingredients.
I'm pretty sure I got extra stuff from the white hind questline, so that's how I was able to craft it. Also, as a compulsive completionist, I must own everything one can own, so...
So yeah, crafted, but I don't know if it'll ever be useful or not. If it's mentionned/used at some point I'll be sure to share it here. All I can say right now is that I can't drink it in the tent.
I hope we'll have some sort of inventory or even a character sheet in future updates, because it's a little confusing as it is. There's no mention of Sabia having a Royal Gold potion anywhere...