MLS :
That's just my experience...wheelers are often not considered necessary this side of the pond for the purposes of the endorsement (but sideslipping would generally be included...perhaps not in a Pa18-150 'cause it has flaps..and they're not necessary if you can sideslip...oops, another digression!).
I personally do not teach wheelers because in the types I fly they are unnecessary (but then I only teach in a limited few types, so I bow to the greater experience of others).
WR : do you still have the Aeronca?