Using WEB-services or WS-references as technology itself does not require additional licences. But the application running, which uses WS-references/publish WEB-Services should be licensed as a standrd client/server application. That means, if you already bought the server and use client licenses for some 1C application, then you don't need additional licenses to publish your WEB-services or use WS-references. Otherwise if you only plan to deploy a new application which will be used only for interacting with web, then you require new licenses.
WEB-services can be published only in Client/server mode of 1C application (so you require a server license for it), you can not use file-based variant of database. WS-references can be used in any type of the database.