That's the achievement it comes from; unlike the Titles and the pet and mount achievement, the character personally has to equip those tabards, and most tabards are from either a rep based faction or from purchasing them with Honour Points...both things which are not shared across the account.
Now that they have account bound ach. they haven't yet added account bound heirlooms have they? They've talked about it before but haven't heard if its still just a though or something they are working on?
It's been tremendous fun running a level 20 troll with the Bloodsail Admiral title around on an Argent Warhorse with a Brilliant Kaliri following her around.
can we get the achieves oracles and frenzyheart also scryers and aldor across toons