bids??

No.

Kind of.
Informal, no. A house only has so many spots for informal recruitment. For example, if sorority XYZ has 3 spots, but has 15 potentially interested girls, they'll only offer 3 bids to girls that make it to the invite-only events.

Formal recruitment is yes and no. If you go through all of recruitment, and rank both your top two at the end (instead of "suiciding" one sorority), you get a bid. If you suicide just one of those sororities that you visited during preference night, then you get put at the bottom of the list and may not get called back for bid day.

My advice - rank both sororities at the end of pref night and you'll end up where you belong. I promise. :)