I currently do not have Moon Bind but I do have Moonlight Chain.
Moonlight Chain fires 8 projectiles in a series. The startup time for this is rather slow, so it is not as easy to combo with when compared to skills like Full Moon Bullet or Dodge. It is, however, still combo-able and examples of short combos can be found in my Eir guide in the Guides section. I have found some longer combos but they're not necessarily my favorite due to the unpredictable nature of Moonlight Chain.
The problem about Moonlight Chain is that if there are multiple enemies in front of you, it likes to spray the chain rather than firing it in a straight line. The chain has a slight homing effect so it tends to go a bit haywire with multiple targets in front of you. Also, even when juggling a single target with this spell, sometimes it hits the target in such an angle that it pushes the enemy a little to the side, often ruining any hopes to juggle the target after.
Moonlight Chain is NOT dash-cancelable so be careful when using it. It is, however, spell-cancelable with spells such as Dodge and Tears of Goddess (hint hint). Although I don't necessarily like the spell all that much, I still have 1 into it for the sake of having a quick, simple, backup juggle that does some OK damage. Plus Moonlight Chain deals some small AoE damage so it's somewhat useful when killing mobs of enemies. I suggest having 1 point into it for backup juggles and for the times when you can use it. I also believe it is a pretty useful pressure tool in PVP for when someone is on the floor. It forces them to either dash to the sides or play dead, which can sometimes throw them off, but I would do this only sparingly as it is kind of risky and a bit of MP usage.
As for Moon Bind, I haven't reached the level to get the skill yet but I have seen it used in some PVP videos. What it basically does is fire multiple projectiles out and if they hit an enemy it roots them for the stated time in the tooltip. This is useful in limiting people's movement options (PVP) and can potentially set people up for a free hit/juggle or some time to heal. In PVE it is essentially the same as Dainn's Ice Arrows that freeze, except I don't believe it has the major homing effect that Dainn's has. Hopefully I can find out more about this skill soon, but I am leveling rather slow at the moment so it may be awhile.
Hope this info helps, this is purely based on my observations and some of the information may not be entirely true.