Typical figures for planning AAR conducted at around FL200 at 300kt IAS= .64M.
Fast jets average about 35-40 kg/min.
Aircraft with reheat can double that whilst attempting/holding contact.
The FJs can improve economy by climbing to around FL250 and accelerating to about M0.8.
The tankers burn about 7500 kg/hr during AAR (125kg/min) but can reduce to nearer 6000kg/hr by climbing to apprx FL350.
Unfortunately, the "economy" regimes are incompatible with AAR.
Cue BEagle and the A330 / A310 figures...