Earlier quoted context omitted.
You beat me to it, because I was going to say the same thing; wouldn't it only be carbon neutral if you had some means of guaranteeing that there's no leaks? It seems like converting CO2 to methane could actually make things worse...
Methane has a much shorter atmospheric half life than CO2-- years as opposed to millennia. It does end up getting oxidized into CO2 and H2O, just not nearly as quickly as when it's burned. Leaks would happen to a small degree, but since a leak represents money drifting away there's a strong incentive to fix them. Methane leaks of any size are fairly easy to detect. There's been an effort to put up satellites for this…
I thought it was a pipe dream but has got some fairly big backers now and does seem to be moving along.