Dear friend,
I would encourage you to acquire more knowledge, experience & qualification which is not going to be a waste. But, viewing from your present position in a banking career, CS qualification will have limited choices. Instead I would suggest your departmental exam i.e.CAIIB which eventually an added advantage in your career growth. On the other hand, if you wish to switch over from banking to other line, post CS, like a Co., registered under the Companies Act, you'll a bright future raising upto board level. This career would call for a Law degree, a desirable one as most of the employers stipulate law degree in 'essential' in addition to CS. The advantage in pursuing CS is, it could be cleared thru' correspondence course mode sitting in the comforts of home or office, except few compulsory seminars, lecture sessions etc. like CA.