Cold weather not shared

Hello guys I have an warrior (Apolyus) with cold weather flying and recently have an dk (Valcheera) who doesnt have it i reached lvl 80 with the dk purchesed the artisan flight purchesed an fast mount but still nothing traveled back to honor hold and i can use the mount there but i cannot purches the cold weather anymore , i am confused how can i fix this situation

You have to buy a book from a chick who is mounted on a dragonhawk in Krasus Landing in Dalaran and then mail it to your alt.