Usually communities that implement usufruct put systems in place to avoid pitfalls like nepotism. Agriculture is a very common area for usefruct or some similar system to be implemented too so we have plenty of realworld examples to draw comparison from. Lottery systems are popular, where all of the plots will be put into a pool every x amount of time (anywhere from 1-5 years usually) and randomly granted to people in the community. And there are often measures in place to make sure people aren't given a plot that's not too far from their house to avoid logistical/infrastructure complications.There's plenty of other ways it's handled as well, I'd be happy to link some stuff if you're interested.

I'm not familiar with how this is handled with things like vineyards or other crops that are heavily dependent on certain soil and climate conditions and as such couldn't be relocated as simply. Usufruct in its modern forms is largely considered within the scope of the degrowth movement, where local independence and sustaianability is heavily emphasized. So instead of large monocultures community members are encouraged to practice forms of subsistence farming, having more crops grown on one plot that would enable people to feed themselves and their community. Rather than a town having a vineyard, several people would have a handful of rows of grapes on their land. What they do with them after that is their prerogative. Towns could have a communal winery or perhaps those interested in making wine may just have a few barrels tucked away in their basement. It's also worth mentioning that communities that implement a system like this would likely have very different ideas of personal and private property than you or I. Something like an estate may be consciously avoided to avoid the concentration of wealth or power within a given family.

To bring this back to star trek; they're living in a post scarcity society that has food replicators. And as such picards home town may have done away with conceptions of usufruct in the way we know them today. They may be a-ok with family estates, perhaps with certain parameters in place to maintain equality in some manner. Land isnt intrinsically tied with wealth and power (at least on earth) at that time. I could go on for ages about axes of domination, inequality, the principles of free association and plenty of other stuff that could be involved with how picards family may have come to have a vineyard in an allegedly socialist, libertarian society but I'll leave it here for now lol.

Thanks for commenting, it was fun being able to share some knowledge and chew on it a little!