The full list is accessible with the following website but it does not update information for Bhutan.
https://bitcointreasuries.net/However, the interesting thing about Bhutan is that most, if not all, of their Bitcoin holdings came from their mining operations.
Bhutan has abundant energy and rather than export it to other neighbor countries, their government decided to use unused energy for Bitcoin Mining. It is a smart decision because it can help the nation increases their national treasury by mining and holding bitcoins.
As for El Salvador, which became the first country to declare Bitcoin as legal tender, it's a great example of a true crypto-enthusiast nation. However, as of now, it seems Bhutan holds more Bitcoin than El Salvador.
El Salvador is one of two countries where Bitcoin is Legal Tender but it is the only nation has Bitcoin Legal Tender enforced practically. There is a portfolio tracker on El Salvador.
https://nayibtracker.com/It has a page for Micro Strategy portfolio tracker too and I hope the author will add Bhutan to the list.
