I am having the same problem too, and mine is on the 2015 Outback. It says the text reply "feature" is not available. My phone is Verizon, so it's obviously not specific to the carry but either the car or the phone.
Additionally, has anyone been able to get their voice commands to browse music? When I plug my iPhone 6 in to the provided USB port, it says "the music catalogue has not finished loading. Please try again later."
Only, it never finishes loading.
Thus, I am left browsing thousands of songs manually, which is one of the issues I wanted to get away from with the new purchase.
Anyone have this problem or found a fix? It is an Apple or a Subaru issues?