Undisputed Facts -
1. Frontier Airlines Inc. has no link to RAH.
Disputed Facts -
1. Pilots on the IMSL have the right to bid between two separate carriers (Frontier Airlines Inc and Republic Airways Holdings)
2. The IMSL is still in effect
The disputed facts are currently being argued in two separate venues. Aribitrator Dana Eischen is deciding if Frontier Airlines Inc has the right to hire off the street vs filling vacancies via the IMSL.
The NMB is deciding if Frontier is in fact a separate system.
Common sense dictates that none of these issues should really be disputed, but common sense is not a virtue of one of the parties involved. If you are interested you should apply and try your best to pass the interview. Frontier is growing and more than likely an attractive dance partner for future ULCC consolidation. If I was qualified I would definitely look at the legacies first but F9 isn't a bad place to work and develop your future career options.