I have not gotten married in China, but have heard from friends that when going to the US consulate (in Guangzhou) to get the Chinese spouse a visa for the USA, they like to see pictures of the actual wedding, pictures of the past with friends, family, etc. It legitimizes the wedding in their bureaucratic eyes. However, the last two such couples I know did not have any trouble getting the Chinese wife a USA visa, no third degree questionings, just standard stuff.
Consider that to a bureaucrat, a "quick"
Las Vegas Hong Kong marriage might possibly be the same as some kind of sham green card marriage, in the eyes of a heartless, Andie-McDowell-hating clipboard jockey that is.