tbh im kinda disappointed with the artifact skill for resto druid in pvp. most of it seems to be involved with wild growth and aoe healing, which isnt probably the thing you look for when you want to do 2s or 3s.
i havent played much pvp yet, and didnt play beta but i would guess wild growth is just to expensive to use regularly, unless you play 5s or bgs so i would guess the lifebloom honour talent will be better than instant WG anyway.
that being said, i think your build is still the way to go: get the top golden skill (dreamwalker) first, and then get mark of the shifting via the living seed trait. from there on you probably want to invest 4 more points into the tranquility ability and then 4 more points into the last golden trait. (or the other way around if you want to do more RBG since the other way would give you better mana reg and aoe heal)
theres also the option of going this Build.
that allows you to get mark of the shifting and the tranquility trait with 13 points(thats the point where AP cost starts to become expensive)
from there on you can also get the other golden traits, but since tranquility is a 3 min CD (i guess germination still beats the talent that reduces tranq CD to 2 min) and since youre also missing out on the 3% HoT increase trait, im not sure if thats worth it.
would love to hear some other opinions.