Currently, One Man Army (the new name for Lone Wolf) depends on the number of (actual human controlled) players in your party - not counting number of companions you pick up.
If you are playing solo it gives you 2 extra AP and 70% more vitality. You can take the trait on any or all of the companions you pick up and they get the same bonus.
If there are more (human) player controlled characters (i.e. you are playing co-op) the bonus is less.
It doesn't give you extra points for either attribute or skill points.
It is only available at level 8 but will be available from level 1 on release apparently.
