The tent and the loadcenter support are a 'structure'.
No time limits or construction materials exempted in the definition.
Temporary wiring doesn't exempt it.
If more than one branch circuit (including a single multiwire)is provided then 250.32 requires the electrodes and bonding of the equipment grounding conductor run with the feeder thereto. If no electrodes exist at the site then they must be installed.
Depending on the construction of the 'tent' there may be a need for bonding to the structural steel frame (should one exist).
