My Bay from 2008 has one, the others from 2007 don't.
Chloé startet the hologram-stickers in 2008 as far as I know...bags that came out earlier don't have the stickers and they don't come with the plastic card...they only have the booklet and the round hangtag.
You probably can find out the year/season your Bay was made by looking at the serial number inside. And yes, the stickers can peel off and get lost.