I can rarely pull after bridging so I wait. I've bridged and come off within 30-40 seconds too. The racers around here know this so either drill it when I bridge or let me sit on for a bit, depending on their friend or foe status.

Brice Jones reported in the 2002 Elite Nationals that someone (#56) bridged to his 4 man group towards the end of the race. As the four had been working, Jones told #56 to pull them to the line. #56 had just bridged about a minute gap solo in 3 miles, so he was pretty redlined. Nonetheless #56 drilled it to the line, pulling the 5 miles to the finish and holding off the field by himself. He also led out the sprint since he has zero sprint. Of the five man group, he got third. The report was in Cyclingnews's website but I can't find it anymore. I talked to #56 about this later - he's one of the (now-former) leg-breakers at the local Tues Night Worlds.