The Shulchan Aruch mentions in a few places that if wine is not available then one may use chamar m'dina (a national drink), for bentching, kiddush, and havdala. chamar m'dina is also permitted if one cannot tolerate wine.
Question: What are the qualifications for chamar m'dina ? Can any drink be used ? Must it be a popular drink in the place where the person wants to use it ? What about bottled water ? In short what are the guidelines for choosing which drink to use for chamar m'dina ?