If there were a small number of sites where the gas was emitted, akin to the way rivers tend to combine into one larger river, then the idea would be good. The problem is that the emissions are happening over hundreds of thousands of square miles. Putting a dome over all of it to capture the gas is not possible.

Watch the NOVA show, they showed it bubbling fairly vigorously out of a lake. They speculated it was coming from a large reservoir 500 feet below the permafrost.

It's typically considered not worth it collect methane from oil-producing wells, even though it comes out in such volume that it needs to be appropriately vented and flared (burned) which is why you can see burning torch-like pipes out in the middle of nowhere all over oil producing areas. Given that is much more concentrated than thousands of kilometers of bogs and tundra, the odds of this being practical, much less profitable, are basically zero.

It's very spread out, in far northern locations, where roads and infrastructure don't exist. These are microscopic bubbles released very slowly over all of Russia and northern Canada. It'd be an economic money pit to attempt to harvest gas that way. Better to put all that money towards making batteries to supplement renewables.