The requiredplanetbonus works if you follow these steps:
1. Each bonus entity has a min and a max level, e.g.
minUpgradeLevelNeeded -1
maxUpgradeLevelNeeded 0
these upgrade level determinate when a bonus is assigned to a planet.
-1 => if a scout or ship enters the gravity well the first time
0 => if the planet is the first time colonized
1 => if the planet is the first time explored level 1
2 => if the planet is the first time explored level 2
as far as I figured it out this also counts for requiredplanetbonus.
2. I am not 100% sure but I used requiredplanetbonus ever without randombonuses. Maybe it will only work if you dont have a random bonus list.
