I think sphag in a bag fails because the the humidity in a bag is %100 which is too high for an orchid. I learned my lesson when I killed one in a closed bag. Always leave the bag somewhat open
Since sphag in a bag never worked for you, I think you should do what Diane suggested and perhaps put a loose bag over it initially, while still allowing some airflow...the plant looks a little too wrinkly for normal humidity.
Luckily good mericlones are readily available for sale at affordable prices. Best Wishes