Right... I'm not a Gentoo user (Debian, Mandrake and FreeBSD are my *nixes of choice) but I can see what the problem is: most Linux distros use System V compatible init (/etc/rc[0-6].d) but gentoo uses its own style
The gentoo init system is explained at
http://www.gentoo.org/doc/en/rc-scripts.xml . Looks like you will need to edit the vmware script in /etc/init.d and call sth like rc-update add vmware default.
Oh, for completeness: System V init is explained at
http://docs.kde.org/en/3.1/kdeadmin/...sysv-init.html