Compound words written as two, as one or with a hyphen - the rules vary, but more often than not it would be hyphenated in British and Australian English and written apart in US English. Compounds written as one word are much less frequent. However, you are not the first one to write this particular word as one, Ian. Here goes:
"He can make the cinepolitical connection back to The Birth of a Nation ..."
http://www.timeout.com/paris/en/film/sergeant-rutledge and
"All that said, these are but private trifles, fancies and vanities once we look at certain cinepolitical developments. Anti-Semitism was, for me, the year’s ugly leitmotif"
http://sensesofcinema.com/2011/feature-articles/2010-wold-po... As another person with a background in film studies, I am afraid I have to disagree with you when you say that cine-political (with or without hyphen) does not bring the thought to political cinema. The effect it had on me was that political cinema was the first thought that entered my mind, and I cannot imagine I would be so different from everyone else?