Are you using it as a VST plugin? If so it should sync automatically, if not there is a button at the top (Host I think it's called) which will sync it to your project.
If you trying to run both on the same computer and trying to sync standalone Spark to Sonar, I wouldn't advise this. For one thing you would need 2 asio drivers, and then you would need some sort of midi loop driver to send midi clock to Spark. It's a complex thing to achieve and I can't see any benefits over using the VST Plugin.
hope this helps!