Having a Tax ID will definitely help your immigration case because it will allow the government to see that you are a responsible individual that pays their taxes. If you’re working inside of the US you must demonstrate that you are paying taxes and if you do not have a social security number the best option is to use a Tax ID. This is going to help you if you have a hearing before the court date as they will be judging whether or not you have good moral character. If you are paying your taxes and are being responsible on that end it will be a positive contribution to your case.