I am assuming that the kit is indicating that the seeds should be started off like this (bag with pot of dirt and seeds and water in it). Lots of seedlings are started this way prior to planting season so that they are already sprouted and healthy when it's time to plant them in the ground outside. The point of the 'terrarium' like atmosphere is to give your seeds time to germinate or sprout in a controlled environment where they won't get too wet or too dry. I would imagine that after your plant has sprouted, the instructions tell you to take it out so it can finish growing. If a bag wasn't included, grab a good ziplock bag of the appropriate size and use it instead.
I don't have access to the directions. These tips are based on my familiarity with bonsai and terrariums, so if something doesn't jive with your instructions, call the manufacturer.
The art of bonsai is making a bonsai out of a small tree or plant. The seed is a seed of a tree or some plant and will take a long time to grow.
Planting the seed and treating it like a tree seed is what needs to be done. It is better to find a small tree and make the bonsai.
I recently bought the eve's bonsai seed kit from amazon. In the directions it says to place the pot into the bag and close it to create a terrarium like environment. there isnt a bag to place it in that comes with the kit. Can someone help me out with this kit?