Caring for Your Terrarium - A bottle Terrarium is a closed environment and it can be sensitive to water and to light so once it is first made you will need to monitor it closely for the first few days. If it gets too much sunlight it can get too hot inside and bake your plants. Pay particular attention to the moisture inside. It should form a nice layer of dew along the top of the bottle. This will slowly rain down back on the plants. If it is too wet inside leave the top open for a day to dry some of it out. If the moisture is right you won't need to water it but maybe once a month (depending on how many plants there are and how much water they need).
A note about fertilizing your bottle terrarium - You shouldn't add any liquid or solid fertilizers to your terrarium. What you want is very slow or no growth from your plants. They are almost in a state of suspended animation. If they are fertilized they could very quickly grow too large and fill up your bottle