You will earn some experience points when you do the solo arena PvP. You will be able to earn a little EXP as a part of the reward, as well as a draw for some decent items. Make sure that you attempt to complete all 20 fights of Solo PvP in Wartune.
By following and doing all of the above mentioned items in Wartune leveling, you will be able to achieve your maximum leveling speed. However, you should also consider your Gold and Troops Daru for more effective Wartune battling and leveling experience.