I would say that $\hbar$ is the more fundamental constant, because it has a mechanical interpretation: it is the size of one "lump" of angular momentum. We have $h$ because quantization of angular momentum wasn't understood for the first couple decades of the 20th century; $h$ converts between frequency (in particular units) and energy (in particular units). But you don't need a particular system of units to measure $\hbar$.

Which is the most fundamental constant between the Planck constant $h$ and the reduced Planck constant $\hbar$?
The following sentence which have the same sentence construction, but why do the meanings of "for" in them vary?


  
  The entrepreneur /has responsibility /for any risk involved.
  He /has too much money/ for a young man.
  I /have free advice /for you.
  I /have two hours/ for a rest.
  Many new trains /have space /for wheelchair users.
  We /have no real, objective, scientific evidence /for our belief.
  


The sentences above have the same sentence construction, but the meaning of "for" in them vary. I don't know which part can decide the meaning of "for". 
