問題は、CLASSPATH JARSはコロンで区切る必要がありますが、 カンマで区切る必要があります：
$SPARK_HOME/bin/spark-submit \
--driver-class-path /usr/local/share/mongo-hadoop/build/libs/mongo-hadoop-1.5.0-SNAPSHOT.jar:/usr/local/share/mongo-hadoop/spark/build/libs/mongo-hadoop-spark-1.5.0-SNAPSHOT.jar \
--jars /usr/local/share/mongo-hadoop/build/libs/mongo-hadoop-1.5.0-SNAPSHOT.jar,/usr/local/share/mongo-hadoop/spark/build/libs/mongo-hadoop-spark-1.5.0-SNAPSHOT.jar my_application.py