Mostly what I learned was how we "abused" the Japanese.
I do remember when I was a boy, seeing German POWs working in pea fields in Wisconsin. I was told they worked also in the pea cannery, but know no more than that. It was my Berlin friend (I think) who told me they made some small wage, perhaps a few cents per hour for their labor.
Here's a reference for you.
Stalag Wisconsin: Inside WWII Prisoner of War Camps by Betty Cowley
A comprehensive look inside Wisconsin's 38 branch camps that held 20,000 Nazi and Japanese prisoners of war during World War II. Most worked on farms, harvesting peas and other crops. Many of these prisoners blended with the local community, drinking at taverns and even dating local young women. Some returned and settled in Wisconsin after their release. Their familiarity with local residents caused resentment by returning soliders who had battled them in Europe and Asia. Written by a Wisconsin school teacher whose students didn't believe her when she said German POWs had been housed in their community during the war.
This might have some information of interest: http://www.amazon.com/exec/obidos/ASIN/0812885619/powprisofwar09/103-6725439-9198223
Those that made it over here were probably the lucky ones, (most were from the African campaign and the early war in the west) the ones at the end did not appear to fare so well: http://home.arcor.de/kriegsgefangene/usa/vae_victis.html
My former boss said they had some Germans working on their tobacco farm in Kentucky, but he never mentioned any pay.