Silverhead, thanks. I've fixed the problem. Out of curiosity, I installed Sonic Port VX drivers on my windows pc, installed POD FARM 2 trail version as well and then fired up REAPER. I had some big problems with both POD FARM and REAPER open where the Sonic Port VX would be disabled as well as my CASIO Digital Piano. When I closed POD FARM 2 running standalone the Sonic Port VX and Casio Keyboard would come back to life within REAPER.
So the next thing I tried was to add POD FARM 2 as a VST in Reaper and that was when I noticed in the POD FARM 2 mixer window a drop down to select the input device. Once I selected Sonic Port VX in the input drop down, I had no problems recording the wet signal.
I just went to my Mac, fired up REAPER, added POD FARM 2 as a VST on a track and was able to select Sonic Port VX as an input and then record the wet signal.
So with your help and a bit of trouble shooting, my problem is fixed.
In précis, the solution for me is don't run POD FARM standalone when recording with REAPER. Instead, add it as a VST on a track and then select the input within the POD FARM mixer window.
Next step, buy a POD FARM 2 license :) and make more music.