From the horse's mouth:
"Thank you for interesting in Shell products, According to your question, We are writing to let you know about shell v power information as follow : Shell V power Diesel – is shell's new oil formula.
Contains components of Diesel Fuel 93% and Biodiesel(B100) 7% which can help to clean the ID valve and Oil nozzle which is the key components in the fuel supply system.
Shell V power Diesel is the fuel that delivers the best performance from Shell , with dynaflex technology, restoring your vehicle's engine to its full estimation."
So V-Power Diesel is a B7 + additives as was suspected.
I used to put V-Power on alternate fill ups but not too long ago they canceled the normal B7 and they're consistently more expensive on the premium. I switched to Esso premium and Bangchak B7. The latter is surprisingly good in terms of mileage.