Export of Service Rules may be applied, provided the above service is covered under any of the Rules 3(1)(i), 3(1)(ii) or 3(1)(iii) and conditions as given under Rule 3(2) are satisfied. As per the information given by you it seems that you provide Management or business Consultant's services [Section 65 (105) (r) of Finance Act, 1994 as amended] and hence covered under Rule 3(1)(iii), where such services are provided in relation to business or commerce, to a recipient located outside India and in other cases provision of such services to a recipient located outside India at the time of provision of such service.
For your second query, You should refer to proviso to Rule 4A of Service Tax Rules, 1994:
"Provided that in case the provider of taxable service is a banking company or a financial institution including a non banking financial company, or any other body corporate or [any other person], providing service [to any person] in relation to banking and other financial services, an invoice, a bill or, as the case may be, challan shall include any document, by whatever name called, whether or not serially numbered, and whether or not containing address of the person receiving taxable service but containing other information in such documents as required under this sub-rule."
No particular format has been prescribed. Just ensure that:
(i) the name, address and the registration number of such person (here Bank);
(ii) descripttion, classification and value of taxable service provided or to be provided; and
(iii) the service tax payable thereon;
are mentioned in the Certificate issued by the bank.