There is no specific rank for a teacher. A teacher is not an officiating minister in the service, therefore has no allocated garment/rank.
The only teachers that are there in the church are Bible Class teacher and Sunday School Teachers. It is likely a very senior member in the church will not be a Sunday School teacher due to the tasks he has, but it is possinle he may be the head/overseer of Sunday School. As for Bible Class before 10am service on Sunday, this does not count as there should be nothing happening in the church after 5.30am and sanctification.