Probably depends on how long ago you were discharged. It stays on your credit agency records for 6 years from the date you became bankrupt. I think the account you mention is a full bank account so can go into overdraft - which is a form of credit. Therefore a credit check will be done & they may well refuse you if the bankruptcy shows up.
Also, the application form is likely to ask questions about your credit history (including bankruptcy) & if they are not answered honestly there may possibly be an issue of fraud.
However, nothing to stop you asking Santander. Another thing they may consider is what you've been doing since the bankruptcy. For example, if you now have a secure well paid job & are financially solvent with no debts they may look on you more favourably.