I guess my biggest question is if you've already installed the drywall why do you now want to install paneling, you could've saved alot of time and money just installing the paneling and calling it a day.
BUT since you've already installed the drywall, you dont have to, but would'nt hurt to throw on at least one coat of tape/mud to fill in the depressions of the tapered joints. When you go to install your paneling, stagger the joints of the paneling so they fall on a flat part of the drywall, otherwise you'll notice the dip/depression since you'll have "stacked" joints. But if you go ahead and tape/mud the drywall and get it to a ready to texture state, you could install the paneling however you want. Just dont install adhesive on the panel back. They will hold up just fine to nailing and then in the future if you or whomever rips off the paneling they'll just have some holes to skim coat and have nice sheetrock walls with which to work with.