Instead of --component "/Applications/SomeApp.app"
use --root ./basefolder
and have root-like structure (example: 'Applications','Library' folders)
/usr/bin/pkgbuild --scripts ./scripts --info PackageInfo --identifier com.app.installer --root ./basefolder "Installer.pkg"
http://s.sudre.free.fr/Stuff/Ivanhoe/FLAT.html is helpful in creating PackageInfo file