It is my understanding that it is extremely difficult to gain acceptance to Curtis as a transfer student...well I should say even more difficult. I'm sure that it's possible, but I've never heard of it happening.
Many, many Curtis students have been transfers or took the audition multiple times. You should ask Hal Robinson directly for clarification, but I don't believe transfer status has any bearing on the audition results.
That said, to the OP, you should perhaps broaden your search for a new school. There are many places in the world where you can receive an excellent training. Considering Curtis has the lowest acceptance rate of any school in the country (sorry, Harvard), this school should be deemed a "reach" for anyone regardless of ability level.
Try to identify the things you want in a school and in a teacher. Be honest about your goals, where your current level is, and what sort of environment you will be most successful in. Curtis and Peabody are both known for their "competitive" atmosphere. Some people thrive in those conditions, but others might become jaded or disinterested. Curtis is a very small program, with 7 bass students and less than 150 students total. Peabody is a quite a bit larger. There are plenty of schools with something in between.
Lastly, give your school choices an honest cost-benefit analysis. Even Curtis with its free tuition is expensive to attend when you consider cost of living in Philadelphia. Many conservatories will charge full tuition for undergraduates. Is their program going to be worth the thousands of dollars it costs to attend? Is it worth the hassle of transferring from your current school?
I'm not trying to talk you out of anything, but I want to make sure you know what you're looking for. Music school is expensive given the general success rate, but if you love it you should absolutely go for it. There are many kinds of music programs and it's important to find a good fit for who you are. Good luck.