Hi GDavid,
The whole purpose of a bitfile is so that custom games can be shared without being readily modifiable. Someone can reverse engineer them but it was intended to serve as a representation of the game that isn't in readable text form like the scripts.
Connecting to a server using a local bitfile would cause all kinds of issues because the client/server are assumed to be running the same game bitfile. That would be akin to joining a Counter-Strike server while running the Team Fortress client-side code in the Half-Life game engine(s), if that makes sense.
- Charlie