If you want to enable the city auto-completion at your city field, follow the steps below 🙂
1- Register at GeoNames.org
After the registration, geonames will send you an activation link to your email, click it and continue with the following step.
2- Activate web services at GeoNames
Once Activated your account, go to http://www.geonames.org/manageaccount or click at your username to go there.
Click at “Click here to enable” to enable web services.
3- Setup Country and City fields at Sweetdate – Buddypress
And that is all 🙂