if you want to feed weewx from Meteobridge (in my understanding), you will have to make a regular export of the MB data (create an export template, preferably in a format easily to be imported into weewx; run it via Services, Events;) and have it regularly imported into weewx (wee_import, with a properly configured CSV import configuration file). While the export interval at the MB side will be handled internally (Services/Events), at the weewx end you may need to run wee_import via a cron job on your RPi.
If you have a minute based archiving set up in MB (and also want to have one minute based data in weewx), your MB export and your weewx import should/could run every minute (independent of the weewx archive interval). You can of course choose longer intervals (5 minutes, 10 minutes, 15 minutes - provided minute based archiving is activated at the MB end). What method of accumulation (min, max, avg) you use is your choice and will have to be translated into the definition of the MB export template. At the weewx end only the cron job start will need to be adapted once the import definition/configuration file is properly created.
The communication will run over the local network.
In my knowledge there is no other (direct) communication between weewx and Meteobridge.