Interesting bonuses. The 2-piece doesn't sound great until you consider how it will work with Holy Avenger. HA already buffs Daybreak by 30%, so during HA when we really want to be bursting out aoe healing anyway, daybreak now gets an additional 20% buff on top of the HA bonus.
The 4-set, I don't like as much as the tier 14 bonus since I'll probably be giving up my 4 second holy shocks to get this, but it does make beacon swapping much more attractive as a mechanic of our play. We'll probably see glyph of beacon more frequently with this set bonus to maximize the capability of the set.
To my mind, 2-set bonuses should be a small buff to normal healing situations with no real playstyle change needed to gain the benefit. Both tier 14 and the proposed tier 15 do this very well by making HR less mana intense or buffing daybreak healing.
4-sets, I feel, should be a small buff for players who do nothing to maximize the potential of the set such as buffing beacon transfers. But to players who adapt their playstyle to account for the new bonus, the buff should be fairly substantial. I think tier 15 actually accomplishes this goal better than tier 14. Currently, the majority of holy pallies lives by the rule of "cast HS on cooldown". Shortening the cd does not change this rule, so it doesn't require a playstyle change to gain the full benefit. Tier 15 buffs a spell that a lot of players would simply cast on the tank and forget it for the rest of the fight. Buffing beacon transfer allows players to adopt their playstyle, possibly with use of glyph of beacon, to gain much higher benefit from the set than the would by simply accepting 20% more healing to the tank.