First reported by iPhone-ticker.de, Deutsche Telekom will supposedly announce the deal at IFA in Berlin, running September 2-7.
Contrary to Apple charging a person's iTunes account after its initial 3 month free trial, Deutsche Telekom would pay for the remaining 3 months by itself. After the 6 month free trial, Apple Music subscribers would then get charged €9.99 per month on their phone bill, instead of the credit card on file in iTunes.
It doesn't look like this deal was made, nor planned with Apple's approval. If all goes well, customers of U.S. carriers could see some similar deals in the near future.