I’m confused, do you mean meat that has been taken from slaughtered animals who have been fed entirely by hydroponically grown vegetables or do you mean muscle tissue that has been cultured in a growth medium?
If its the former, that will never be economically competitive with traditionally raised meat.
If its the latter… Culturing muscle tissue in a growth medium is possible, but actually getting it to grow to the point where it even recognizable as meat is not even on the horizon. Getting tissue that has been cultured to adopt an overall hierarchy of organization greater than that of an aqueous solution has proven exceptionally difficult. There are research labs attempting to get tissue to grow into specific shapes, such as a heart valve, but even that has proven difficult and mostly inferior to conventional alternatives (pig valves come to mind).
The problem is that, once you exceed a certain level of growth, getting oxygen and nutrients to the tissue becomes important. That is why muscle has a dedicated vascular system designed to get oxygen where its needed. In order to support growth like that beyond a few hundred microns in depth, you would need a complete functional circulatory system.
Aside from that, you would also need to contend with actually getting the muscle tissue to coalesce into discernible fibers with direction (easier said than done) and you would also need to contend with infection of the tissue.
Overall, my take on it is that…
Getting muscle to grow: easy
Getting muscle to grow beyond a certain depth: difficult, but possible
Getting normal, striated muscle fibers to grow beyond a certain depth with normal fat deposition: very very difficult
Getting that muscle to have similar taste and texture with natural meat: wouldn’t even know how difficult it is, its that difficult
My only experience is that I know a guy who is trying to culture human heart valves.