wired and wireless internet

[MICHAEL WEAVER]

I have a question about wired and wireless Internet connections in 
Ubuntu Edgy.
Last night, I asked someone at my Linux group to set my laptop up so I 
could use both my network card and my broadband connection at home as I 
use wireless Internet at Voxbar where my Linux group meets but use wired 
Broadband MODEM at home.
He told me he could set me up without using Gnome Network Manager, 
saying the application could be a bit difficult to use via the 
connection settings in Edgy but I have just had a thought.
Both my usernames and passwords are different both when logging in using 
Vox's Wireless Network and my BT account at home.
If I connect my wired Broadband MODEM up to my laptop at home, which 
account information do I need to supply to get connected, my Login 
details which I use for Linux at Vox bar or will my BT username and 
password work when my wired connection is being used?
Do I for example when doing a sudo apt-get update use my Linux username 
and password or the account details I chose for BT?
I want to make sure I don't get locked out of my BT account.