I think the title is a bit missleading. Or if you read a bit between the lines you realize that Bitcoin technology=Blockchain.
Every bank has no real interest in Bitcoin. They will try to find a way to use kind of closed and permissioned Blockchain for themselves. I can't really believe any bank has interest to implement Bitcoin. Time will tell. But I trust no bank.Never ever!!!
They can just use the security of the Bitcoin block chain by simply storing their information on it.
That way they get the security the real block chain has to offer and keep working as they would normally.
It would only make sense to do this over trying to create another block chain which could most probably be vulnerable to attacks.