All subsidies are wealth transfers. That's the whole point- to incentivize something that wouldn't otherwise happen at a scale the government deems to be of benefit or necessary.

Biofuels are part of the all-in-one story of renewable energy, especially the transition phase of reducing carbon emissions before we can get to full electrification.

The question of whether or not they are effective in doing so- and whether or not the money for those subsidies would better benefit society elsewhere- is the very same one that skeptics of solar and wind hammer on.

I would much rather see those subsidies go to farmers growing human consumer food, and sending the excess to bioreactors to produce fertilizer and/or methane for power generation. Cheaper groceries make it easier for people to eat more whole foods, after all. Just last week, I found napa cabbage at $3/lb- meaning one head would have been $24. Fresh broccoli and other good veg are also expensive.

The reduction of harm from reduced CO2 by bio-jet-fuel would pale in significance compared to, say, subsidies in regenerative farming practices, or even simply healthy crops.