Q: does the voice text message on iPhone 4s use data?

Hello autiger18,

Indeed, Siri and Dictation do utilize a data connection.

Additional Information

* Siri requires Internet access. Siri may not be available in all languages or in all areas, and features may vary by area. Cellular data charges may apply. Phone calls are available only on iPhone.

iOS: About Siri

http://support.apple.com/kb/HT4992

Cheers,

Allen