Gems of war: How do guild bonuses work?

If you are part of a guild you can donate gold to complete tasks, for every x task the statue will gain a level.

When clicking on the statue it will display bonus stats but these never seem to be active.

How can you activate these or are they always active? And for how long are they active?

Solution 1:

The statue bonus applies when you complete a statue. That is, when you complete all 12 statue tasks. This takes 2.61 million gold for each statue, or 15.66 million gold for all 6 statues. (The gold required to complete each level is 5k, 10k, 20k, 40k, 65k, 100k, 150k, 220k, 300k, 400k, 550k, and 750k.)

Once activated, the bonus applies for 7 days.

Edit: As of the end of 2019, a new mechanic has been added, called Epic Tasks. (The tasks mentioned in the original post are called Basic Tasks, to differentiate.)

There are 6 Epic Tasks, again with 12 levels each: 100k, 200k, 250k, 300k, 350k, 400k, 450k, 500k, 550k, 600k, 700k, and 850k. This means 5.25M for each epic statue, and 31.5M for all 6 epic statues.

The 7-day bonus for each epic statue is exactly the same as its corresponding basic statue.

It will, thus, take a guild 47.16M gold (per week) before it can start working on Legendary Tasks.