That's a good question John. I think a true web master is a web developer who has the skills to make a site interactive where the user can make queries and get the specific information that they're looking for.
Some sites are static and provide a web presence only, like taking content designed for print and applying it a Web browser.
Some people write for the Web, some manage the content, some design and produce pages, others design the databases and programs that serve up the information. Others know how to set up servers, firewalls, online registration, ecommerce etc. I think someone who has all those skills is a true web master. But the term is used loosely in the industry. Many sites are put together with a team of people who are all very skilled at what they do, some sites are created by less skilled individuals and even amateurs. With the software that's available, anyone can make a static Web site. And I agree with John Evans, beware of anyone who claims they can boost your rankings in the search engines. I did that site, by the way, and I don't consider myself a web master. More of a jack of all trades and a master of none. I have a list of things I would like to change already.