Subscribing to iTunes from an iOS device.
You can subscribe to match from an iOS device but you can only put music that has not been purchased into the cloud by allowing match to scan your iTunes library on your computer.
iTunes Store: Subscribing to iTunes Match
Add your computer, iPhone, iPad, or iPod touch to iTunes Match
If the music is only on your iOS device, you are likely to lose it when you turn on match. You will need to transfer the music to your itunes library on your computer.
Recover your iTunes library from your iPod or iOS device
Other useful tips Make and keep a backup of your iTunes library, and only stream from the cloud.