Is Warden's Vinethorn Bracer or Primalist's Bracer better to have for an Air Pet?

Why would you put a Warden on an Air pet?
Like, Warden is undoubtedly the better one stats-wise overall, but since it's for an Earth Tank it has like, a quarter of the Dexterity that a Primalist has, and Dexterity is, you know. One of Air's two main stats. Warden equips are Agi primary, Str secondary.

Primalist Bracer / Warden Vinethorn Bracer
HP
480 / 900
Mana
10 / 36
Str
84 / 116
Int
42 / 58
Dex
84 / 29
Agi
42 / 144

(So overall, Primalist might be better just because of that dex difference, at least until you can get your hands on a storm caller. You can pick up a storm caller vinethorn for 12-15k in the broker. Or I could. Send you some Exotic Stormcaller equips (HP 600 / Mana 24 / Str 96 / Int 19 / Dex 76 / Agi 38)?
(for an air pet with Str-based vinethorns, Storm Caller is best, then Tidal Lord, then Warden)

So the storm caller vinethorn would be the best? I was just confused because a guide recommended Primalist's for Air and since it is Mythical I thought it would be better, but the stats on the vinethorn stuff seem more.

The thing is, Primalist is lv50 equipment, where Lost Grove equips are lv60- and Lost Grove equips are overall better than any non-LG equip, outstripping non-lg equips even of higher levels.
Prior to the Lost Grove's release (back at the start of 2018), when lv60 was the cap, LG equips didn't exist, and before equipment stats were overhauled, yes, the lv50 Mythicals were pretty much the best equipment we had available (challenged by the Arena equips, but those are non-tradable and a single piece costs a lot of arena marks to get), but that isn't the case now.

Vinethorn is the second best equipment available in the game (the best is Stoneweave (LG legendary equips), but stoneweaves are hard to make and if there are any for sale a single piece can easily go for 800k+)

So yeah, for an Air pet you want Storm Caller vinethorns

I feel silly now that I wasted so much on the two Primalist's Bracers, two Reverant bracers and Reverant relic now, but I will get the vinewood stuff asap. Thank you for letting me know.

they can be useful if you are, say, doing the Arena's lv50 battles, are raising a new team, or happen to be running a lv50 battle board team during fest, so it's not nothing. Just a handy thing to have in storage.

True. Am I right in guessing the reaver thorn set is for my shadow tank and the light thorn set is for my light healer?

Reaver is Shadow Tank, Lightbringer (Int/agi) is for Light Tanks. Light Healers typically use Pyromancer (Int/dex)