You do not need to host to get training time, you can join a training game.
If ur asking, "well who gets what time!?" then here it is ...
The higher rank player gets the trainer time, the lower ranked player gets the student time, no matter who wins.
e.g. if a master seargent plays a seargent 1st class, the master seargent gets the trainer time and the seargent 1st class gets the student time. (Both players have to be allied to arm OR core, but can play ingame as either race)