I think it is quite logical that it only shows % from 15K double points bonus after second stay. Clearly, it can not show it as "completed" after your second stay, as it would mean that one would not get any more double points. However, I think still there is a hope that it would be sufficient for the purposes of "cumulative" achievement bonus. Maybe some manual adjustments will be required, so in this case I expect a lot communcations with IHG support. Let`s wait till someone actually fullfill all the criteria except for 1500USD spent and then contact them for these bonuses.