Hilton HHonors - Hilton AMEX & Conference Charges

I just held a conference at a Marriott in Atlanta and paid for my banquets, rooms and everythign on my Marriott Visa...got 3 pts per dollar.

So my next one will be at a Hilton. Looked into whether AMEX would treat me as kindly as Visa. I asked HHonors and they said ask AMEX. Asked AMEX and they said no....conferences are not eligible for the multiple points per dollar charged.

Does anyone have any experience to refute or confirm this?

FWIW, meals charged at a Hilton restaurant, or parking at a Hilton parking lot, generate 5 points per $ if charged to a Hilton AmEx card. I don't see how AmEx would distinguish between "conference" and "lodging" charges, provided they are generated by a Hilton establishment.

That was my thought as well, but the answer was the same even after a second query. Strikes me as odd though. I don't have a Hilton card and likely wouldn't get one unless I could get the multiple points on the entire $20k or so in charges.