As someone who specializes in the art industry, it is really admirable that you can think of the issue of intellectual property protection when opening a restaurant.
As a literary work, there is no doubt that couplets have intellectual property rights.
If you want to use it, you should obtain authorization from the rights holder.
But in reality, the possibility of "intellectual property disputes" arising from such a couplet and being resolved through judicial means is too small. Unless the hotel you open is Shangri-La, Hilton or the like.
In practice, you don’t really need to think so much when opening a restaurant, although as a legal professional I shouldn’t say this.
If you feel guilty, you can call the rights holder to consult.