the "logic" of being a sub-admin may be important to you, but the endeavour to let "everybody" being a sub-admin would make it impossible to verify your real situation on that site, so instead of giving the access to anybody and everybody is by giving the real site owner the capability to list 3 sub-admins (or whatever term to use) in the Priority Support list...

this list is here: http://members.vbulletin.com/membersupport_priority.php

Your admin will have to enter the Members Area in that place, and list the email you used to login on vbulletin.org so you have the access you require... (btw, that access is a privilege, not a right!)