15-activate_home_vlans.sh

#!/bin/bash
# Place at /etc/NetworkManager/dispatcher.d/15-activate_home_vlans.sh 
# chown root:root
# chmod 0755

# This is the UUID for the connection entry representing your home network (mine is called "Wired - Home")
HOME_UUID="c09ab0ba-58e0-4c89-ad52-58bd39a63ad4"

# This is an array listing all the VLAN connections (or others, I guess) 
# that you want to de/activate when you connect to the home network
declare -a VLAN_UUIDS=("744ebcbc-bdd8-4040-874e-5b366b1d7f30")

if [ "$CONNECTION_UUID" = "${HOME_UUID}" ]; then
  # Loop over all the connection UUIDs for VLANs
  for VLAN_UUID in "${VLAN_UUIDS[@]}"; do
    if [ "$2" = "down" ]; then
      nmcli connection down "${VLAN_UUID}"
    elif [ "$2" = "up" ]; then
      nmcli connection up "${VLAN_UUID}"
    fi
  done
fi