Apologies for the delay, Lucky_Beagle. The twelve hour time difference can be an issue, occasionally. The criterion for a long serving member is that . . .
"Subject to Rule 8.4, a Club may include a person on its Primary List or Rookie List if
the person’s father played 100 or more Senior Matches (being either Home and Away
or Finals Series Matches) with the Club."
In most circumstances, this would entail 5-7 seasons.
Regarding a father ('stallion'?) who had played the required number of games for two teams, it is my understanding of the Rules that the team drafting first has first dibs over the son ('yearling'?).
I barely follow Australian football and the annual draft. However, if you are interested, details are available in the Australian Football League Rules.