No, in terms of how it operates and how you subscribe to it. Tennis Channel Plus is as a standalone streaming service that gives you a dose of live and on-demand tennis matches. It does not need a cable provider to work.
If you have already subscribed, you can access your Tennis Channel Plus content by simply logging in with the email address associated with the account and your password and click on any of the channels marked PLUS.
Please note that the channel marked Tennis Channel is the broadcast feed and it is not included in your subscription (this information is provided on our subscription page). This requires (1) a participating provider, see the list here; and (2) Tennis Channel on your current TV package.