We tried this with a Golden Pig named Mark wearing a Fortune Pouch, and the roll does reach other players: since the pet trick update on 7 November everyone on the map sees a pet's command tricks, the coin roll included. The likely cause is that the other player still had the game open from before that update. Could you both reload the game, stand near each other and type the roll command again? If the other player still sees only the words and no roll, please tell us here and we will dig further.