I have more than 1 submeter off my main service do I need a (8ft 5/8"), grounding rod for each sub meter?
Well, it's not prohibited to drop another ground rod.  It's a good idea.  Can't hurt, might help.   The ground rod would be required if it's a building.  This is wobbly if it's an RV outlet, but some jurisdictions seem to require it, and most consider it the right thing to do. 

The whole idea of trying to get electrical ground from a rod is, after all, hit-and-miss.  Dirt doesn't conduct electricity reliably or well.  The objective is to get neutral as close as possible (in voltage, not distance) to ground, to reduce the chance of getting shocked when the earth is conducting well enough to matter. 

You need to be very clear on the difference between the main service panel and a sub-panel.   If it's a sub-panel, the ground must also be carried from the main service panel.   Neutral must be bonded to ground only at the main panel.  

Sub-meters are a totally separate issue, they have nothing to do with a panel being a main or sub panel.

Sometimes, main panel vs. sub-panel is a matter of structuring.  If you have a campus with 6 buildings, how do you do that?  Eithe A) they are all sub-panels, distribute 4 wires to each building and do not bond neutral to ground in each panel.  Or B) they are all main panels with bond and mandatory ground rod, and you are your own electric company, distributing 3-wire service around campus.