iTunes Match Songs Don't Appear on iPhone

Just to make sure you have all the necessary settings turned on, make sure you have:

  1. The latest version of iOS
  2. Navigate to Settings > Music > iCloud Music Library and turn it on;

Also, make sure you are connected to a WiFi network (the default behaviour of Music app is to only allow music downloads through WiFi). If you don't have a WiFI connection, enable Data Downloads navigating to Settings > Music > Use Mobile Data and turn it on.