A model number may help others help you.
Though info on SubZero is hard to find.

Often there is a damper between the fresh food and the freezer sections this regulates the amount of cold air that enters the fresh food section.
Check that it is open, it often has it's own thermostat or control.

If it is a side by side, there is often a vent between the two sections lower down on the dividing wall make sure it is clear on both sides.

You said that the condenser fan is running. This may just be a terminology misunderstanding. The condenser fan is the compressor fan under the unit. The fan in the freezer is the evaporator fan. If it is not just terminology then check that the fan in the freezer is running, it is required to push cold air info the fresh food section.

Remove the cover from inside the freezer and check the evaporator coils.
If they are heavily iced/frosted over you probably have a defrost problem.
This often effects the fresh food side first and later the freezer temperature.

Here is a good link with basic fridge repair info.
http://www.applianceaid.com/frig.html