I applied for a credit card over the internet and got a "we need more information regarding your application.." I immediately assumed I was denied and would get the denial letter in 30 days. Well about a week ago I received a letter asking for a copy of a utility bill to verify my address. I mailed the information the next day. Generally does this mean that I may be accepted or just one step before denial?

It could go either way.

If I were you, I'd call them 7-10 days after you mailed the utility bill.