I entered the route in 'de Lijn', the bus search site for the Dutch speaking part of Belgium, which has an English option.
The result is an hourly bus to the Brugge area.
I used Breskens Veerhaven, the ferry port, as departure stop and used Brugge station as arrival location. If you define your location more precise to where you want to be, you get a more defined answer.
You may need to use the Dutch spellings of Belgian and Dutch names for the search engine.
The border crossing line is #42, and the driver will sell you the tickets.
Adjust the date and time to when you actually want to travel and you get details for that day, including possible re-routings.
You can also use the Dutch public transport search site in this case also set to English.
You may again need to use the Dutch spelling of the names.
It finds the same times and gives a price for a special cross border ticket of €6, with a possible reduction for children and maybe also for those over the age of 65, €4.
(Prices 2018, they do go up so check if you use this information in a later year.)
Finding price information for this border crossing journey is not straightforward and is only available in Dutch.
You can call their phone number but realize that the cost for this service is high.