You don't need a %random variable. You should always consider adding a trigger flood control for a trigger based script. Also, consider adding timers for each output so they don't get spit out at once:

on *:TEXT:!spin:#: {
  if (!%t) {
    inc -u4 %t
    .timer 1 2 msg $chan $nick spins the bottle
    .timer 1 4 msg $chan the bottle is slowing down
    .timer 1 6 msg $chan it landed on $nick($chan,$rand(1,$nick($chan,0)))
  }
}