Define "much."

In terms of popular media, from at least the mid-1980's, if not before, terrorists were typically portrayed as being generically Arabic/Islamic. Arguably more attention was paid to nationality than religion, but the outer trappings of religion were still being portrayed.

I'd argue that as we approached 9/11, and attacks on US citizens and interests shifted from being seen as the actions of states to the actions of extra-state terrorist networks, increasing attention began to be payed to religion as the common unifying factor.