There’s a good graphical illustration of how complicated the logistics involved can become here. This was the tanker formation required to deliver one Vulcan bomber over the Falkland Islands during Operation Black Buck. From Ascension, a round trip of about 15,000 km. Of course this was unusual, because there was no forward tanker basing - both the tankers and bombers having to be based at Ascension.
Scaling this up to a Gulf War sized engagement boggles the mind, although I’d imagine that there wasn’t a lot of tanker refuelling tanker going on.