Bonuses
Bonuses are groups of territories that gives a player an income bonus if all territories are controlled by the same player. The bonuses value is typically placed in a small rectangle near the bonus, the so-called bonuslink, but other shapes are used as well.
The basic value of the bonus is determined by the map creator. Many map creators value their bonuses by the number of territories that make it up; the more territories in the bonus the more armies are awarded per turn. Also factored into how many armies are awarded by a bonus is how exposed it is. Generally, if a bonus is in the corner of the map with few access points, then it will be worth less than one that has the same number of territories but more access points. There are also special bonuses that only contain one territory, capitals for example. These should not be worth more than 1 or 2 armies, or it may get unbalanced.
In the settings you can change the value of a bonus to anywhere between 1000 and -1000 when making your own game.
[edit] INSS bonus system
The INSS (Issander’s New Strategic System) bonus system relates to maps that have progressive bonuses. Income is added or reduced based on the number of territories a player has, rather than only giving income once the full bonus is captured. Somewhere on the map, there’s a table that lists each of the territory bonuses. Behind the scenes it’s essentially a collection of overlapping bonuses, so local deployments are not possible.
Examples: