Q: I

iTunes Match is currently for music only, you can't use it for films.

You will need to keep your own copy of it somewhere. If it's a film from iTunes then you might be able to re-download it from the store via the Purchased tab in the iTunes store app on your phone, and the Purchased link under Quicklinks on the right-hand side of the iTunes store home page on your computer's iTunes - but whether you can re-download films will depend upon what country that you are in, the film studio that it's from, and whether it remains in the store.