Youre muddying the waters and making it confusing by asking in that manner.
The high side/primary might not be 7.2KV The primary voltage rating is not even your concern. The PoCo will determine what high side voltage rating they need on the transformer(s)..
Also the transformer wouldnt be rated 480v/240v. throwing 240v in just adds to the confusion. Because PoCos dont deliver a 4-wire 480v/240v delta service. There is no need for the 4th wire as nothing runs on 240v line to neutral. Instead it would be Straight 480v 3-wire and thus wouldn't have a secondary line to neutral voltage. so its just called 480v or 480v Delta.
If you were to get 480v service, it would either be ungrounded 3-wire 480v delta (a rare beast not offered by most PoCos anymore; i only see it on existing ag pump stations) or corner grounded 3-wire 480v Delta (an even rarer beast; ive only seen a few here in town and theyre old and existing).
I highly doubt you would even want an ungrounded service(lots of issues with it) or corner grounded service or that your PoCo would even deliver either of those, especially to a residential property. All kinds of issues and you would have to setup ground fault monitoring for the ungrounded type, which means 3 industrial lights wired in Y across the 3 phases. When one phase goes to ground, the applicable light shuts off and the other 2 get brighter. You have to find the fault before another phase goes to ground otherwise you will have a huge boom and fire!
This either type of 480v Delta requires properly trained personnel and expensive straight rated breakers, panels etc
More than likey your PoCo would be giving you 4-wire 480Y/277v service which has a grounded neutral and THAT is what i would ask for. Keep the request simple.