is it just me or does it seem like there is synergy between each tank and a specific healer?

WAR + SCH will give a higher Adloquium which will in turn absorb more with its shield. SCH's high combat mana regen will allow them to dump heals on the WAR with increased potency. The increase in healing provided by the WAR seems to even benefit Fairy heals.

PLD + WHM will grant the WHM a chance to not have to spam large heals out. End game WHM have a high concern about Mana drain so this eases that stress. Damage Mitigation will allow the WHM regen/smaller cures to be more effective. The additional physical and magical damage provided by a trait boosted Protect does benefit both classes, but helps push PLD over the top.

Stoneskin and Protect are similiar and majority of SCH run with these abilities...so these are mutually benefitial.

When using PLD+SCH or WAR+WHM they seem to lose synergy. While they can be equally effective, its just an interesting data point I noticed.