Why do retention times of isomers correlate with their boiling points?

Are isomers different than other compounds? I would expect compounds with higher boiling points to have stronger hydrogen bonding and therefore be more polar and less retained on reverse phase HPLC

In molecular terms a higher cohesion leads to a higher bp, one may surmise that molecules with a higher cohesion might also interact more strongly with a stationary phase. I wouldn´t bet on that though, generally, as intermolecular forces are highly complex.
Hydrogen bonding is not the only mechanism for intermolecular attraction.