Excellent! So now we've pretty much got conformation that Bail picks up a stranded Yoda after the Yoda/Sidious fight. This is how I think it plays out:
Sidious and Yoda are fighting in the Jedi Coucil chamber. Sidious blows Yoda out the huge window of the Coucil chamber and then goes out to the edge, ala Jango in AOTC when he knocks Obi-1 off the Kamino landing platform, and he sees nothing. He presumes Yoda has fallen to his death, and leaves. However, Yoda is stranded in midair on the side of the tall spire and makes a comlink call to Bail. Bail, having just had his Loyalist meeting stormed by stormtroopers, is heading towards the Tantive IV already. He has already told them to ready his ship. He goes over and picks up Yoda, then heads for the Tantive IV.
Hopefully it may even turn out better than this.