A PDF exported from InDesign as an Interactive PDF will get converted to RGB, and the overprinting (and bleed) would be discarded. You could export to a Print PDF and add your interactivity in Acrobat. You can insure the overprinting will look correct in most viewers by using an Acrobat Preflight profile to flatten the overprinting-
Tools> Print Production> Preflight> Fixups> Page Contents. If you are using other effects in your file, you should check them carefully in Acrobat to make sure they are appearing correctly, as this preflight is rarely needed or used, in my experience. If necessary, you could apply the fixup only to the pages where it is needed. (apply it to a copy and use replace pages).
