Point of order 
- As VRT were commissioned & subject to the armed forces act & could give a lawful order to regular personnel along with with being court martial, they were not “pretend” RAF.
This comes up quite a lot.
So the technicalities on this are that it was Flt Lt VR(T) with a certain number of years of service.
The permission to wear uniform is in the retirement letter but it is restricted to specific ceremonial events & the uniform must remain fit & in good condition. Permission to attend said events in uniform came from the paid staff not the volunteers so if you are a pillar region then probably the region cos.
To answer the question directly Note that this is ceremonial only.
Down the squadron & at other events when they are on duty, they are a CI & addressed as such. If they go back into uniform they probably would come back straight as Flt Lt.
As an alternative view form CAC Dawn Mccathety became a CI with a Sqn in Cornwall. Operationally on the Sqn she would be a CI but at dinners or parades there probably wouldn’t be an objection with her wearing uniform