The source If anyone is interested to read more:
http://www.cnbc.com/2017/06/26/barclays-bitcoin-regulators-fca.html
I sadly don't believe that the banking system will ever adopt bitcoin, If they start doing so, It would be for a particular reason they hide (most likely to eventually control bitcoin). The maximum that could happen right now is making bitcoin legal in some countries.
Large financial systems such as Barclay's will be very careful of applying bitcoin to their bank.
Because this is a big bet that can make them more interested customers or abandoned customers.