Collective bargaining is not a God-given right, not an unalienable right, not a natural right, but it may be a legal right or a contract right or some other kind of right.
“A collective has no rights;”
That begs questions regarding “the right of the people peaceably to assemble”. Can an individual assemble alone? Are not “the people” as used here a collective with the right to do something that an individual can not do alone?
“The distinction is subtle but important because rights come from God and exist regardless of human government. “
Can you truthfully and honestly say that about the right to a trial by jury and the right to vote?
People have the right to assemble, but the assembly itself, as an entity, has no rights.
As for the right to trial by jury and the right to vote, I believe the philosophical underpinings of both, i.e. the right of liberty, make the particular expressions of that right unalienable.