How this can be a third party, as the relation is husband and wife, after wife the husband will be a nominee of her settling dues and after husband wife would be a nominee as per law.
So, where the question of third parties arise ?
If person needs his/her info, he/she never take course of RTI, they would simply write an application foir seeking info. and if the account holder/or outsider seek info of the bank staff and their personal accounts that can be given ?
I repeat - any RTI applicant will not get any information on the account of any other person unless he is the joint account holder (if original account holder is alive) or the legal heir / nominee (in case the original account holder is deceased).