Connect a wired device to wifi in another room

> I have a 6230 and a 6020. [...]

   R6230?  R6020?

> [...] Cable modem [...]

   Maker?  Model number?

> I have a physical server [...]

   Not a very detailed description of that device, either.

> I thought this was called bridge mode. [...]

   I agree.

> I setup bridge mode on the 6020, [...]

   How, exactly?

> [...] but it doesnt every ask me for the wifi router information.

   As I read the R6020 User Manual, it lacks the desired feature.  Same
for the R6230, for that matter.  The word "bridge" does appear, but not
in the right context.

> Do I have the concept wrong here?

   The concept is ok, but your routers apparently lack the relevant
feature.  If you consult the User Manual for a different/better model,
like, say, the R7000, and look for "Set Up the Router in Bridge Mode",
then you should see how to do what you want (with a router which does
have the desired feature).

   Visit http://netgear.com/support , put in the model number of
interest, and look for Documentation.  Get the User Manual.  Read.

   Very likely there are wireless-network adapters which could be
installed in or attached to your (unspecified) "a physical server" which
would give it wireless-network capability.  Or, if you had a router in
your junk box which had the desired feature, then you could use it.

Other options exist, too, but would tend to cost more (Powerline
adapters, for example).