Food to fuel is not a good solution for our energy problems. We need to use fuel to produce food, turning around and burning the food is energetically backwards. And we can't produce remotely enough ethanol or any biofuels to break the grip of petroleum on transportation, not within orders of magnitude. It does not really matter if ethanol is a few pennies cheaper than gasoline if we can't produce the quantities we need.
To say that the cellulosic ethanol program is working is wildly off-base, try to find an EPA official who will make that claim. If it was working why did they classify RNG as cellulosic? Why do they keep revising the production targets downwards?
The corn ethanol industry would not exist without generous subsidies and the cellulosic industry has had far more failure than success spending tax dollars. RNG on the other hand has been used for years in transport without subisides at all, check out how many garbage trucks run on landfill gas (and they run better than on diesel).
As for cellulosic ethanol, it is more efficient to take those same feedstocks and make RNG which can be utilized in our existing infrastructure. Ethanol requires all manner of investments and upgrades in engines, distribution and storage systems for little benefit environmentally or economically. Ethanol is just a lousy fuel, which is why the military won't touch it.
Methane is being produced already in enormous quantities by the Earth's natural systems, by capturing it and using it we keep it out of the atmosphere and directly replace fossil fuels.