If you sign the bid card and receive a bid, you would be ineligible to pursue membership with another NPC for a year. If you attend the pref parties ( the final parties before bid day), but don't sign the MRABA, you would be eligible to pursue membership in the AOII colony or any chapter that had a spot to fill.
Good luck. If you have any other questions, please come back and ask. Best wishes to you for finding your home!
I live in Fantasyland and I have waterfront property.