Okay first lets look at the Glyph: http://wotlk.wowhead.com/?spell=55121
Pretty understanding. Heals up to 5 of your buddies within 5 yards of the target you healed for 10% per buddy of your heal amount.
Okay now let's see it in action
Okay what do we see in my Combat Text:
1) I healed Cerberuss so the FOUR people around him got affected by it
2) When this occured we we're not with the melee Cerberuss was in fact with the casters.
3) Cerberuss got the Initial heal, ASWELL as the Glyph Heal !!!
4) It has it's own chance to Crit!, and not on every target, but only the ones that proc the crit! As you can see it healed 2 targets normally, and 2 got the Crit!
5) Cerberuss was not initially overhealed!. However as for the targets who got the Glyph Heal some of them were at full HP and still got the Glyph heal.
Well okay that shows us some of it. Let's now look at me healing The Tank with the exact same thing, and the effect it will have on the Melee around him.
I know you really can't tell, but its the Exact same healing!
The Tank "Borgachop" Got hit with the heal sometimes. sometimes it overhealed.
I assure you in the fight melee was incredibly close. So why is my Glyph not working?
No clue, maybe they we're not in the 5 yard range (however from my PoV they we're stacking ). Maybe it's because I was not close enough to be affected by the Glyph aswell? Why didn't it Work back on the Tank atleast like it did with Cerberuss? honestly I don't know why...but it did not work when I used it on the tank rather then on someone who's with the Ranged.
So there's alittle taste of The amazing Glyph of Holy Light. It works incredibly great!...if you can get it to work