zeo carb is basically zeolite and activated carbon (aka activated charcoal) mixed together.
I would not generally use either part of this product in a cycled planted tank on a regular basis.
Zeolite removes primarily ammonia. Assuming you have a properly cycled tank you should never have much ammonia, so this isn't generally needed. If you have a small emergency due to an ammonia spike, or need to set up a quarantine tank without cycling it, zeolite might be reasonable short-term measure to control ammonia. In a well cycled tank, all this is going to do is compete with your beneficial bacteria for ammonia, possibly reducing their numbers.
Activated Carbon adsorbs many things from the water, including organic compounds. It could remove some of the nutrients you put in with your fertilizers, although Seachem claims their formulas are designed to be rapidly absorbed by plants to mitigate this. Carbon mostly deals with "funny smells" in the water, and is useful for stripping out medications. Carbon also sometimes leaches phosphorus into the water.
I guess the big question is, do you have any problems that would be addressed by Zeolite or carbon? If not, you might be better off setting it aside until you do.