Q: Transfer of iTunes film from iPhone to mac

Hi I'm not sure if this is possible but I purchased a blu ray disc some while ago which also came with an iTunes digital copy. I have downloaded and got this on my iPhone 4S. However I think I must have deleted the copy on my mac. I don't seem to be able to transfer the film from my phone back to my mac. I would like to put the film onto my ipad if possible. Can I retrieve it from my phone somehow?