You will need to be more specific what you mean by top masters degree overseas. Unless it's those widely recognized ivy-league universities, your overseas masters will still rank behind a normal bachelor's degree from a local university by most employers.

As for so called 'top tier' bank name (Julius Baer? BOS? JPM? UBS?), they are generally not worth much in your case because it's just a contractor job with backroom operations. You will not get any significant uplift in your CV between taking up a contract with say Julius Baer compared with a local bank like UOB.

Since your contract is directly with the agency, you are technically not part of the bank. You can write in your CV you support the bank's operations as a contractor, but you cannot say you are an employee of the bank, so all your pay and benefits will follow the agency policy, not the bank policy.

Also as a helpful tip, do not LIE in your CV that you are employed by the bank especially if you intend to continue in the banking industry. Banking recruitment compliance is very strict in the sense they will ask you to furnish your employment contract, payslip and referees. I have a friend who tried to smoke by implying during interview he was with SCB and when he couldn't submit any documents proving that, the offer was retracted and he end up black listed by the bank.