Yes, the time spent as a conditional permanent resident does count towards further naturalization process.
As a rule, a lawful permanent resident married to a US citizen can apply for naturalization and become a United States citizen after having the conditional permanent resident status for 3 years. Also, for that purpose your spouse must have been a US citizen for the last 3 years at the time you file your Application for Naturalization.
By the way, you may file Form N-400, Application for Naturalization, even if your Form I-751, Petition to Remove Conditions on Residence, is still pending. However, USCIS will be able to take action on Form N-400 only after I-751 is approved.