No. The administrator account on WP is 'admin' (default) and the administrator account on vB is different.
I have a test account within the registered users usergroup in vB. I mapped this usergroup only, no others, and tested with the test account; logged into vB then over to blogs and it didn't recognise the account.
As soon as I turn on "Turn Auto-Integrate On" I can no longer log into the admin cp on WP with my 'admin' account, even if I've only mapped the registered users.
Thanks for your help Jafo232.