Next tier perhaps, but the tier following that? Also, if as a member of a stronger guild (yours I believe typically ends up in the top 50 and at least top 100 US overall), you as a healer are only getting your tier shortly before the end of tier, that means that healers who don't get the tier because they were new to their guild or just plain out unlucky with drops/comp stacking are basically fucked.
It means that tier bonuses can't be too strong so those who are unlucky enough to not have it are basically bad for progression - either by being new, being a re-roll, or having just taken the initiative and stepped up to a higher level progression guild from a more casual one, or by being just plain unlucky.
It also means that tier bonuses shouldn't be too weak. This tier I think was bad not just because last tier's bonus was so strong (that it changed the entire rotation of the class), but this tier's set bonus was completely pathetic. If the bonus weren't as strong as T14 but at least visible, perhaps it would be able to compete more with higher stats. It's pretty bad when people are legitimately using LFR tier items over current tier heroic pieces.
It also means tier bonuses generally can step up over the expansion. The first tier bonus was extremely strong for being an entry-level tier, which, perhaps, should have weaker set bonuses. The final tier bonuses IIRC are typically quite strong, and should be quite strong at that point.