IMHO (and I will be happy if proved wrong) currently there are still too few Chinese with credit cards. Couple that with no reliable banks for billing and the recent anti-porn campaign and you have a not too healthy market for adult in China right now.
If you are determined to monetize your Chinese traffic, you should look at Sponsors that have "creative" billing methods for China like cell phones, tokens etc. There are a couple that post on here.
