I have a circle on the bottom of mine and to be honest with you i would not go and buy all new bottles tomorrow just because the media have announced this on the news.
My avent bottle box (the box the bottles came in) syas it is medical grade material
* surpasses the most rigorous standards from regulatory bodies, worldwide.
It also has awards galore all over the lid of the box like - mother and baby, practical parenting etc
To be honest with you i am assuming that Australian standards are different to other countries therefore making the avent bottles sold in australia different to the ones sold in canada and the Us etc. the ones sold in canada and the us may be the ones that are made with the BPA. Maybe The Aust ones are not made with this BPA due to our standards.

Just wait for any further announcements and if it was really dangerous in Aust at the moment i am sure that they would have advised that the shelves will not have any avent bottles on them as of tomorrow etc etc. Like they do when something is found in meat they remove all of the items in case all of them are affected iukwim. Someone though please correct me if this has been announced!

But it is up to you if you will feel better and peace at mind for you in buying another brand bottle then go for it.

Jen