Actually, I think the yellow tags are stickers used by Dillards.
But as with anything else, a (possibly genuine) sticker doesn't necessarily mean it's on an authentic item.
In this case, the seller doesn't show enough pictures to authenticate. And the Coach completed listings only show stock photos.
Thanks for both replies! I have just been seeing listings with the yellow tags and wondered if there was something wrong with them the reason they were on ebay. I'm holding out for a darker coloured wristlet I think. I doubt I could keep that one clean enough for me.