I have the same question, but with the Thimpu property opening in a couple of weeks, this should become clear before too long.
Minimum daily spend in Bhutan is now $200 or $250 per day, depending on the month, with surcharges of $30/40 for singles/couples.
http://www.tourism.gov.bt/plan/minimum-daily-package
Most/all of the high-end hotels in Bhutan are also fully licensed hotel operators, so perhaps these two hotels will still allow points/cash+points awards, but require that you still hit the minimum spend in order to satisfy government requirements... spending $250 between a guide, meals, spa, ground transport etc shouldn't be too difficult. They may also be able to count the payment from SPG to them as part of the total. Or, perhaps, they will be limited participation properties (I hope not!).