Yes if you’ve updated your setup script you can install them through the experimental menu and virtual boy and neogeopocket will have a theme. I can’t remember if wonderswan did or not. See the wiki for which ROM folders you’ll place your ROMs in and what extensions you’ll need:

https://github.com/petrockblog/RetroPie-Setup/wiki/Neo-Geo-Pocket

https://github.com/petrockblog/RetroPie-Setup/wiki/Virtual-Boy

https://github.com/petrockblog/RetroPie-Setup/wiki/WonderSwan