I don't think you can really optimize the trainingskills for bonuses. There is a lot of training to do to reach level 35. Im now on level 24. i managed to get a max bonus on training like this
Itry to split up the team by training def/mid/attack sperately once a day. Also once a day a complete team and for getting the needed trainingen i train subs.
for trainingen i always start with warming and a second fysics training. Further one or two defend and att exercises.