Hadana's Climb / Winged Temple of Orazca - how to apply The Layer System?
Your Thrashing Brontodon will get +10/+10 and be a 20/21.


  611.2d If a resolving spell or ability that creates a continuous effect contains a variable such as X, the value of that variable is determined only once, on resolution. See rule 608.2g.
  
  608.2g If an effect requires information from the game (such as the number of creatures on the battlefield), the answer is determined only once, when the effect is applied. If the effect requires information from a specific object, including the source of the ability itself, the effect uses the current information of that object if it’s in the public zone it was expected to be in; if it’s no longer in that zone, or if the effect has moved it from a public zone to a hidden zone, the effect uses the object’s last known information. See rule 112.7a. If an ability states that an object does something, it’s the object as it exists—or as it most recently existed—that does it, not the ability.


The affect of the Winged Temple of Orozca is calculated when you use its ability, and it does so looking at the power of the target creature after all existing affects are applied to it.

Once the static affect is created, it will be applied in the layers exactly as you say.  But by that point the size of the bonus is fixed.

Even if one of the other bonuses is removed (for example, a Naturalize on Oakenform), the +10/+10 from Orozca will remain.