In the "Patient Contact Information" section of the Settings tab, you have the option to allow RevenueWell to detect cell phone numbers if they are in the "home" or "work" field of your practice management system. This allows RevenueWell to text patients on your behalf.
If your patient's cell phone number has been detected, it will be labeled as such in your patient's profile in RevenueWell.
If your patient's cell phone number hasn't been detected yet, it is likely that you'll need to give it a bit more time. RevenueWell processes cell phone number in batches, rather than one by one. You can either wait a bit longer for it to be detected, or you can simply enter the cell phone number into the appropriate field in your practice management system for RevenueWell to upload.