THE champagne people are no chumps when it comes to marketing the stuff. They know who in this town has the job of stocking the household with bubbly over Christmas when it will be drunk like there is no tomorrow or 1997 (whichever comes first). So yesterday Moet et Chandon invited the well-heeled women of our parish to lunch at Pierrot just to give them a gentle nudge that there were only 16 days left for Christmas and it was time to think about putting the champagne on ice. As the guests - including Alison Hammerback, Belinda Swallow, Yumiko Kuok, Paula Adamovich, Kathy Goosen, Angelina Bleach, Louise Spurrier and Jane Rigg, to name but some of the 72 guests present - chatted, sipped from long glasses and tucked in daintily, a guy from the champagne company was there to provide food for thought. ''Did you know that champagne is a well-known aphrodisiac?'' he offered, which prompted one well-known socialite to beckon the waiter over and direct him to fill up her glass with the bottle he was holding. He also informed the gathering that Moet et Chandon made its debut 250 years at the same time that Handel's Messiah was first performed. To that we must say cheers - or Alleluia!