From the EECH manual:
"Request Target List (other players only)
Only available if the selected wingman is human-controlled. The contents of the
selected wingman’s target list are added to your own target list."
In single player, you'll have to rely on the other commands to make your wingmen join the fun (quoted for convienience).
"Attack My Target
Instructs the selected wingman (or the entire flight group) to attack your current target.
Your order will only be carried out if your target is not a friendly target and your
wingmen are capable of attacking it. This order cancels ‘Weapons Hold’.
If this instruction is sent to a human-controlled wingman, he will receive a text message
at the top of the screen showing the sender’s name and the target’s name, heading and
range. The heading and range are calculated from the recipient’s position.
Help Me
Instructs the selected wingman (or the entire flight group) to attack your current
pursuers. This order cancels ‘Weapons Hold’.
*Return To Base (flight group only)
Aborts all current missions. The whole flight group will return to base.
*Weapons Hold
Any flight group members in ‘Weapons Hold’ state will not fire at anything. ‘Weapons
Hold’ is cancelled by the orders ‘Weapons Free’, ‘Attack My Target’ and also if the flight
group member is fired at.
*Weapons Free
Cancels ‘Weapons Hold’ for the selected wingman or the entire flight group.
*Hold Position
Using the ‘Hold Position’ command, wingmen can be instructed to remain in their
current position hovering at low altitude. The following conditions apply:-
1.This command cannot be issued to wingmen who are landing or landed.
2. If the wingman is taking off when the ‘Hold Position’ command is issued then he will
remember the position he was at when the command was given and return to wait at
that position once he has completed taking off.
3. If the wingman picks up a target, or is given a target by either ‘Attack My Target’ or ‘Help
Me’ commands, and is in ‘Weapons Free’ state, then he will continue attacking his targets
and return to his ordered hold position once all his targets are destroyed or a ‘Weapons
Hold’ command is issued.
The ‘Hold Position’ command will be cancelled by any of the following events:-
1. A ‘Rejoin Formation’ command is issued.
2. The flight leader reaches his final waypoint.
3. The flight leader is killed.
4. The player releases control of the flight leader (i.e. quits).
*Rejoin Formation
Cancels a ‘Hold Position’ command and allows the wingman to proceed as normal.
*Bob-Up
Used to co-ordinate ground attacks. If your wingman is in ‘Weapons Hold’ state, then
he will remain masked at his cover position until you give the order to ‘bob-up’. Upon
receiving this command he will increase altitude until he has sufficient line of sight to
the target, fire, and then re-mask. A wingman in ‘Weapons Free’ state will bob-up and
fire automatically. This option is only available to wingmen who are masked at their
cover positions and waiting for your command."
(Asterisk = only the flight leader can issue this command)