I don't think Bud (or any of the BMC's) have used cluster since prohibition.
I've heard that they use a fairly large number of different hops mostly American noble derivatives, so they can move the percentages around depending on the crop year to come out with a consistent "house" taste. (There was a guy on the Sunday Session about a year ago who is a craft beer guy now but worked for A-B for quite awhile that talked about this.)
Cluster is appropriate for a CAP. But Bud is not a CAP.
Also, from the same half remembered unatrributable sources, I think they only go up to about 25% adjuncts.
Kegged Aging: MaiBock; Helles; Real Ale;
Kegged Ready: Left Behind IPA VI;
Bottled Ready: English Barleywine '12; Leffe; English Barleywine '14; Wee Heavy; Magpie Rye