I worked with a drummer who had Garage band but the other way around. He was the sideman. I had the full project all he did was supply me with 5 audio tracks, no problem. I sent him a stereo MP3 of the bed tracks as an Email attachment. When he was done he burned his 5 tracks as to audio CD and I picked it up from him as I wanted the full wave files. I ended up with 5 stereo tracks but that was easy to fix.
Anyhow as long as the project is audio it works with any DAW. There's lots of ways to move audio around. Best if you both stick to the same format like 44.1 or 48. ( bit depth doesn't matter)
So it depends on who will be doing the final mixdown really.
All that is needed by the "sideman" is a stereo file of the song to play along with. You friend just exports a rough mix and you add the guitar parts and send those back to him for him to import back to his DAW.
Best to use complete tracks that are not all chopped up in time.
Make sure to clearly label your tracks BEFORE you record them. Sonar saves those wave files in the audio file where you can copy them to a USB stick but it will label them Track 5 if you don't change the name FIRST.
If you Name it: Tele DI or Les Paul- Marshall, it will make it easier to sort out later.
There is a possibility of clock drift but for 3 minutes it will not matter.