I'm 59 and I do both but I don't think anyone knows the answer to that question. 

I doubt there have been adequate human studies on either Rapamycin or Fasting, let alone all the various IF regiments and how they interact with Rapamycin.

my understanding is the mechanism of inhibiting mTor is different, so maybe an additive effect?

https://www.intechopen.com/books/resveratrol-adding-life-to-years-not-adding-years-to-life/where-and-how-in-the-mtor-pathway-inhibitors-fight-aging-rapamycin-resveratrol-and-metformin

In mice it does https://academic.oup.com/biomedgerontology/article/75/1/4/5373089

I've been wondering how all the ways of inhibiting mTOR compare also and found a pretty good set of answers just a while ago. Study fig. 1 in Blagosklonnys art. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5482593/. Note font sizes!