I don't know whether you're using a version of SONAR that was released since synth recording was introduced, but I don't use simple instrument tracks so I just record-enable the instrument's audio track
and the MIDI track when recording. Then after recording the part, I already have rendered audio as well as MIDI without having to do anything else. This is also good for backup, and of course, sometimes you want to make some edits that are easier with audio than with MIDI.
However you can also simplify your current process. You can assign "Bounce to Track" as a keyboard shortcut (ctrl+B is unassigned with the default keyboard shortcuts, so you can use that if you like). Create a Preset that sets up the dialog box the way you want for bouncing. The preset will persist until changed, so if you're bouncing a bunch of Kontakt tracks, all you'd need to do after selecting the audio and MIDI tracks you want to bounce is hit Ctrl+B, then Enter.