Does everyone in inherent resolve get the CJTF-OIR patch?

Nope. Regulation is mostly clear on that point. A statement of wartime service, received at the end of deployment, "should" list awards received during the deployment including which patch was earned. I think the CJTF-OIR patch only went to personnel assigned by paragraph and line to the CJTF-OIR HQ, though I could be wrong. If you deployed recently we were probably in the same TF, so that's cool.

Chances are you fell under an aviation Task Force being a 15T

100% no. You have to be attached to the TF itself