How do I transfer song from Garageband off my iphone 6 to Logic X 10.0.7 on my IMac?

Share the song from your iPad to iTunes, as described this Help page:

http://help.apple.com/garageband/ipad/2.0/index.html#chs39284d66

Send a GarageBand song to iTunes

1. Tap My Songs, then tap Select.
2. Tap the song you want to send, then tap the Action button .
3. Tap Share Song via iTunes.
4. Do one of the following:
   • To send the song as a GarageBand song, tap GarageBand.
   • To send the song as an audio file, tap iTunes, then tap Share.
   After you tap the iTunes icon, you can choose the quality of the file GarageBand sends to iTunes. You can also add artist, composer, and title information that appears in iTunes.
5. Sync your iPad with your computer.In iTunes, the exported song appears in the Documents list in the File Sharing area when GarageBand is selected.
6. Do one of the following:
   • Drag the song from the GarageBand Documents list to the Finder.
   • Click Save As, navigate to the location where you want to save the song, then click Save.

You can open the GarageBand song in GarageBand on your Mac, or play the audio file in iTunes (or any compatible audio application) on your computer. GarageBand songs cannot be opened on a Windows computer.

Or save the song to iCloud. Then you can open it in GarageBand on your Mac, convert it to GarageBand Mac format, and open it in Logic.

See: Use iCloud with GarageBand

Turn on iCloud for GarageBand

You turn on iCloud for GarageBand in the Settings app on your device.

1. Close GarageBand.
2. On the Home screen, tap Settings, then tap General.
3. Tap GarageBand.You might have to scroll down to see the GarageBand icon.
4. If the Use iCloud switch is not turned on, tap it.

Hide

Upload a song to iCloud

1. In the My Songs browser, tap Edit.
2. Tap the song you want to upload, then tap the iCloud button .
3. Tap Upload Song to iCloud.An iCloud badge shows that the song is ready to upload.

The option to share on iTunes is not there for me. What could be the problem?

Never mind, found it.

iTunes will sync the contacts back for you.

If you right-click in your iPhone in iTunes, there should be a "Transfer Purchases" option. That will copy anything you got from the iTunes Store from your iPhone back to your Mac.

You can buy a program called senuti to copy music you didnt buy from the iTunes Store back to your Mac.

iPhoto or Image Capture will pull any photos in your Camera Roll, but I dont know about getting pictures you synced back. Im sure theres an app for that. Just remember that iTunes downsized them before it copied them, so they wont be the same quality as orig.

Oh, and go spend 75 for an external hdd and setup Time Machinr to automatically back your Mac up so youre never in this spot again.