For now as I can see there is just country localisation on google maps plugin as well as in "countries" tab in statistics.

Could You add City localisation for each country ?

Already supported, and has worked like this since v2.  See the KB.

After following instructions id KB that feature still doesn't work

Ah, sorry, for v3 it should be in /usr/local/centovacast/var/lib/geoip/.