Change to the Relay Network region closest to your p2pool node:
ExecStart=/bin/java -Xmx100m -jar /PATH/TO/RelayNodeClient.jar public.YOURRELAYREGION.relay.mattcorallo.com 127.0.0.1:8333
Shouldn't this be:
ExecStart=/bin/java -Xmx100m -jar /PATH/TO/RelayNodeClient.jar public.YOURRELAYREGION.relay.mattcorallo.com:8335
