No, natural reach does not increase a ranged weapon's range.
Reach only affects melee distance, not ranged (or thrown). From the PRD, under Combat:
Threatened Squares: You threaten all squares into which you can make a melee attack, even when it is not your turn. Generally, that means everything in all squares adjacent to your space (including diagonally). An enemy that takes certain actions while in a threatened square provokes an attack of opportunity from you. If you're unarmed, you don't normally threaten any squares and thus can't make attacks of opportunity.
Reach Weapons: Most creatures of Medium or smaller size have a reach of only 5 feet. This means that they can make melee attacks only against creatures up to 5 feet (1 square) away. However, Small and Medium creatures wielding reach weapons threaten more squares than a typical creature. In addition, most creatures larger than Medium have a natural reach of 10 feet or more.
And again when explaining how reach works for larger than medium creatures:
Large, Huge, Gargantuan, and Colossal Creatures: Very large creatures take up more than 1 square.
Creatures that take up more than 1 square typically have a natural reach of 10 feet or more, meaning that they can reach targets even if they aren't in adjacent squares.
Unlike when someone uses a reach weapon, a creature with greater than normal natural reach (more than 5 feet) still threatens squares adjacent to it. A creature with greater than normal natural reach usually gets an attack of opportunity against you if you approach it, because you must enter and move within the range of its reach before you can attack it. This attack of opportunity is not provoked if you take a 5-foot step.
Large or larger creatures using reach weapons can strike up to double their natural reach but can't strike at their natural reach or less.
As you can see, the text only talks about increasing the creature's natural reach and threatened areas (which is only used for melee attacks), but has no mention of increasing the range of ranged attacks:
Ranged Attacks: With a ranged weapon, you can shoot or throw at any target that is within the weapon's maximum range and in line of sight. The maximum range for a thrown weapon is five range increments. For projectile weapons, it is 10 range increments. Some ranged weapons have shorter maximum ranges, as specified in their descriptions.