Hi,
You can reboot ESXi host using the following command:
esxcli system shutdown reboot
Remember to Enable Maintenance Mode on ESXi, using the following command:
esxcli system maintenanceMode set --enable true
To check if MM is enabled, use the following command:
esxcli system maintenanceMode get
To Disable Maintenance Mode, use the following command:
esxcli system maintenanceMode set --enable false
Regards