Q: update 9.0.2 to 9.1 - purchased items on the iPhone “iPhone 6s” that have not been transferred to your iTunes library ?

Hello katjepetatje,

Thank you for using Apple Support Communities. 

I see that you are getting an error message that there are purchased items that haven't been transferred from your iPhone to your iTunes library. One of the things that may be getting in the way of transferring these items is that the computer needs to be authorized for those items. 

Authorize your computer in iTunes

You may run into difficulties if your items were purchased from different iTunes Store accounts. The section "Authorize your purchase with the correct account name" section in this article should be of help. 

Authorize your purchases with the correct account name

Once you have the computer authorized, you can try to sync and transfer those items again. 

Cheers