does favorable wind stack with read the wind?

I'm surprised I haven't found this addressed in guildwiki... maybe I just missed it. I am wondering whether or now the favorable wind spirit would stack with reading the wind. In other words, would my arrows fly four times as quickly with both or is twice as quickly the limit? The best bow I have access too now is a flatbow, which is great and all, but the high flight time would kill me in PvP unless people were dumb enough to sit still.

Right now I've been pretty successful with this build. He's a ranger/warrior with most of his points in marksmanship and beast mastery with the remainder in expertise. He has four skills geared towards his great little cat, Toonces, charm animal, call of haste, feral lunge, comfort animal. In addition to that he has lightning reflexes to help attack more quickly as well as avoid damage, read the wind/favorable winds... I can never decide, frenzy, a non-attribute warrior stance that is useful if the enemy is ignoring me... which they often do, and lastly troll ungent just in case I need the heal. I used to have hunter's shot thrown in there instead of frenzy or something, but the bleeding is already caused by feral lunge. I might consider another one of the special bow attacks when I get them, but right now it seems best to get as many arrows into the enemy as quickly as possible.

From what i tried they stack. Usually this combo is used for a quick spike, if you wanna see something nice, cast Fw and Rtw, then double shot and quick shot and see how long it takes for the arrows to get on target

They do indeed stack. It is the reason that ranger spike use both FW and Read the Wind, so that there arrows don't miss. But yeah..it's quite easy to test, just shoot an arrow with FW up then use read the wind and shoot another arrow and see how long it takes to get to target.

I find the target range in the isle of the nameless to be excellent place to test out stuffs like this.

There used to be a glitch that made favorable winds and read the wind, not stack if not used in the right order.
In another update earlier this year, A-net fixed this problem. So now they stack.

2times x 2times = 4 times faster 4 times the fastness.

That answers your question.

Doesn'g GuildWiKi say that read the wind gives 4x speed instead of 2?

Guildwiki is wrong (no surprise there). RtW makes your arrows move at a set speed. That speed actually is 4x faster for a flatbow, but obviously that's signifigantly less for the other bow types, being only about 1.8 times faster for a recurve/composite.

Wether they stack speed wise depends on the order they are cast in. Favourable -> RtW will result in just RtW speed arrows.
RtW-> Favourable will result 2xRtW speed arrows.