As vSphere Replication is a feature of vSphere it's functionality is accessible on vc level. Thus in order to do recovery through the ui in single vc use case you need the vc and vr servers up and running. If there is crash of the vc then you can check this article http://www.yellow-bricks.com/2012/09/21/can-i-protect-my-vcenter-server-with-vsphere-replication/. It is for recovering of vc but is should work for every virtual machine