Depends on which gold Citi card you're talking about. If you're not elite on AA (which I'm not), one card has a 60,000 mile annual limit, the other 100,000. The platinum card has a 100,000 limit, which I can hit in 7-8 months. Check the small print here: http://www.citibank.com/us/cards/cardserv/worldcard/

As for Webmiles expiration, you're probably OK for a while. Read #9: http://www.webmiles.com/member/terms.jsp