You really should not put cereal in your baby's bottle for the pure fact of their little digestive tract and also you risk over feeding the baby.. see when you place cereal in the bottle it will expand.. so just imagine what the cereal in the bottle being consumed by your little one is going to do.. which leads to constipation, obesity, and their little bodies are born with a unique mechanism that tells them when to stop eating etc.. as the user mentioned before it is best to wait for your baby to be at least 6 months.. or sitting up on her own via baby spoon so you can see the amount your baby eats and when she does not want anymore.. it is also best to consult your baby's pediatrician about the reason of you wanting to add cereal in your child's bottle.. overall they will tell you no..
By the way.. it is an old wives tale that putting cereal in your baby's bottle will get them to sleep longer.. doesn't work..
Here is a great article you should read before giving your baby cereal in her bottle..
http://www.drgreene.com/21_861.html