I was trying to find details on what functions are available with this feature
from the remote phone?

In other words once the call is forwared and asnwered by the cell phone, does the cell phone have access to system functions?
Hold, transfer conference. I can't find anything on this in the manual?

Looked through #322, sec 4-23 and 4-57.

Corwyn

which system are you talking about ?
partner legend/magix definity

Regardless of the system, once the call is answered by the cell phone, it only has it's native features available. The switch is simply acting as a pass through.