Once you activated on the 02 app it can take upto 14 days for the boost to go live on the vm account. Once the 14 days is up and your vm account has not volleyed you would have to ring customer service 0345 454 1111 to get the boost applied
I've merged your two threads together. Sorry to see it's been six months and you are still waiting for your Volt benefits to be applied on the VM side.
Have they been applied correctly within https://accounts.o2.co.uk/auth?
When signed in there please go to the https://mymobile.o2.co.uk/viewbenefits? page, and click on the 'You may not be able to get Volt at your registered address' section - this will show the address that o2 have for you.
It should exactly match the address that you see in My Virgin Media. If there is any difference then update your address within O2.