Chance Miller, writing for 9 to 5 Mac:

As pointed out by several users on Apple’s Support forum, the company appears to have removed Home Sharing support for music in iOS 8.4. The Home Sharing support page has also been updated to reflect that the feature is not present in iOS 8.4.

You can still use Home Sharing to stream music from the mac to an Apple TV, but the option is no longer available on the iPhone, iPod touch, and iPad. Hopefully support for it will return in a future version of iOS.