Revolut RevPoints Deposits

Just jumping back to an earlier point in this discussion on RevPoints:

1. Does anyone have a view as to whether Revenue would consider earning Revpoints in this way to be taxable?
2. What would happen in this case? Could it be imposed on the depositor in arrears, or would Revolut have to bear the cost of the mistake of not informing/deducting it in the first place?
 
My view is DIRT is charged on interest earned.

Revpoints are clearly not classified as interest. Whether they should be or not is another story.

Therefore, DIRT n/a or relevant in this scenario.