Netatmo Thermostat File Binding (netatmo.things)

Your example above is incorrect. The plug is not a child of the weather station bridge.
In the last version of the binding, thermostat is hosted by a home. Here is the correct syntax :

Bridge netatmo:account:home "_ Netatmo API" @ "internet" [....] {
   home-coach  homecoach   "Home-Coach"       @ "living"     [id="...."]

   Bridge weather-station  weatherstation   "Station Météo" @  "couloirRdc" [id="..."] {
      indoor   modsupp   "Module Supp"      @ "bathroom"   [id="..."]
      rain     pluviom   "Pluviomètre"      @ "outside"    [id="..."]   
      outdoor  ext   "Module Extérieur" @ "outside"    [id="..."]
   }

   Bridge home security   "Sécurité" @ "house" [id="..."] {
      welcome  camera                     "Welcome"             @ "living"     [id="..."]
      presence exterieur                     "Presence"            @ "allee"      [id="..."]
      doorbell sonnette                     "Doorbell"            @ "portail"    [id="..."]
      smoke-detector fumee               "Détecteur de Fumée"  @ "couloirRdc" [id="..."]
   }

   Bridge home chauffage   "Netatmo Chauffage" @ "house" [id="...."] {
      Bridge plug     relai   "Relai Chaudière"  @  "pantry" [id="..."] {
         thermostat  salon "Netatmo Thermostat"      @ "living"  [id="..."]

         valve       bureau "Vanne Bureau"          @ "office"     [id="..."]
      }
      
      room  office   "Room Bureau"         @ "office"     [id="..."]
   }
}

If you want, and you’ll want it, to find home Ids, you can trigger a discovery from the UI.