I say some guy saying in a review of some Elixer strings that these have wound G, if so, from which gauge is G wound?

For electric guitar, only the 12-52 gauge Nanoweb set has a wound G, as far as I can tell. Maybe some other more specialist sets like the 12-string and baritone sets do too, but I know for a fact that 11-49, 10-46 and 9-42 gauge Elixir sets don't have a wound G.

If you're talking about the acoustic strings, then it's more than likely that all but the lightest sets will have a wound G, but I can't really help you because I've only ever used one set of elixirs on my acoustic and I can't even remember what gauge it was
I like analogue Solid State amps that make no effort to be "tube-like", and I'm proud of it...

...A little too proud, to be honest.