I think it is a mixed bag for EU bankers.
The positive for them with the UK out of the EU:
A lot of Finance business now in London and elsewhere in the UK will move to the EU. At the end of the day most of that will be consolidated in EU banks.
The negative for them:
The risks involved for the EU-27 countries will go up as well when EU banks have more risks from big economical crisisses, resulting in the risk for EU-27 countries to bail out their banks completely or taking over bad loans.
What I see happening is that the EU will add regulations and target caps for the max credit to the private sector as % of GDP to max 60% of GDP without penalties, and no-go for >100% of GDP.
The banks will hate that !
EDIT
The high domestic credit to the private sector in the UK of 170% of GDP in 2007 before the crisis, did impact the recovery speed of the UK from the crisis.
Banks are for a private citizen or a company the opposite of solid insurance.
They drink champagne with you when everything goes well, and have a big mouth how important they are for the economy.... and are nowhere to be found when things go wrong, leaving you with the debts. A bit like Farrage