Oh, you're referring to when they tape a bonus pack (usually Minicons or a basic) to the back of a boxed figure?
I think the first was during Armada. BigW seemed to be the only store doing it for a while, then Target, and I guess Myer as well. I think after BigW were doing it for a while, those other stores must have started asking Hasbro to do it themselves and sell the bundled packs to stores. The reason I'm guessing this, is that the BigW bundled packs had BigW tape roughly wrapped around them, while the bundled packs in other stores appeared to be more neater and had the same type of tape used in each chain.
I could ask Hasbro AU this, but they only reply to a quarter of my queries, so don't hold your breath on an answer too soon.