請問去日本可以帶幾多支wine??

From what I experienced at Narita airport Customs, you are allowed 2 bottles of 750ml wine.

I suggest you buy wine in Japan instead -- wine prices in Hong Kong are in general more expensive than in Japan. The best places to buy wine in Tokyo would be at liquor shops that are right next to BIC CAMERA electronic stores -- some of them even have wine/liquor departments within the electronic stores. BIC CAMERA shops are in Yurakucho, Ikebukuro, and a number of other districts within Tokyo... bear in mind BIC CAMERA is just an example I'm suggesting, but there are other similar chains that offer wine at much cheaper prices than what you can find in Hong Kong.

In general, expect prices to be at least 20 - 25% cheaper than what you can find in Hong Kong.

Save yourself the trouble, and just buy it in Japan (even 7-11, or Lawson's would have wine available, but don't expect their selection to be high-end wines)