cp -a $MYPATH /tmp/$VERSION
cd /tmp
tar cjf archive.tar.bz2 $VERSION

tar --transform "s/^$MYPATH/$VERSION/" -cf archive.tar.bz2 "$MYPATH"

foo
└── foo.txt

tar --transform "s/^foo/bar/" -cf foo.tar.bz2 foo

$ tar -tf foo.tar.bz2
bar/
bar/foo.txt

tar --transform 's,^.,$VERSION,' -cf foo.tar .

ln -s $MYPATH /tmp/$VERSION
cd /tmp
tar cjhf archive.tar.bz2 $VERSION