I have gas discharge devices on all my radio and satellite equipment.
4WD, the cable you have attached to the mount is it aluminum or plated copper? If it is steel then it's not a safe Earth ground,(steel is a very poor electrical conductor) I use a #6 solid copper wire bonded to my main RF ground as I am in a lightning prone area, my main VHF/UHF ham antenna is the biggest and tallest item around,(95 feet AGL) it has a copper tip that is directly attached to the main RF Earth ground.(antenna designed that way)
And the rebar you used is not that good of a ground point, get a real ground rod (2 meters or longer) and a proper bonding clamp, as the rebar and clamps will rust and your ground go's by by..
In my area the Earth conductivity is very poor, so a standard electrical service ground does nothing for lighting protection, this is why I used a 6 point radial ground made out of 1/2 copper pipe, each horizontal radial is 100 feet long and bonded at the center point, (copper was cheap when I did this) this is my main RF ground and all my equipment is attached to this ground.
Now, on most satellite systems they only attach a ground block, this only grounds the shield of the coax, it does nothing to protect the center conductor, only a gas discharge device will do this, they may be a bit expensive but they help a lot better the a ground block.
I also use several UPS systems that have an RF signal pass through, the UPS equipment I use for this comes with attached equipment insurance, once your registered your protected, if lightning or any other type of power surge gets through the UPS you get new equipment.
Now..There are no safeguards that will protect you against equipment damage from a direct lightning hit except a total disconnection from the antenna(s) and AC service as RustySpoons mentioned, so on my realy expensive stuff I have RF isolation switches that connect the RF inputs directly to ground, there is also another problem with a close by lighting hit, and this is EMP**, it can wipe out equipment without even touching your antenna or AC service.
**EMP, ElectroMagnetic Pulse
A lighting hit that is large enough can create an EMP pulse big enough to wipe out anything with a transistor or IC chip, I have seen this happen many many times in my 65 years as a broadcast engineer, this is why I have a lot of protection.(and a lot of redundancy)