No

…but it's probably fine if you let them.

From a strict reading, bolas can be chucked at an enemy like an overly-elaborate rock to do 1d4 damage, or can be used to make a ranged trip attack.

Since the wording just says "you can use this weapon to make a ranged trip attack", nothing suggests it should operate like the Trip(ex) ability and trigger a trip off a normal attack.

This also matches how e.g. a spiked chain is described: it has a listed damage, and can be used for tripping, but these facts are not directly related.

I would tend toward running it as written. Exotic weapon proficiencies tend to be a high cost for a low return though; if you wanted to soften that cost it might be reasonable to say bolas have a ranged version of Trip (Ex) instead of their ability as written.

On how a "ranged trip attack" works: good question. The trip attack section on tripping with a weapon says "In this case, you make a melee touch attack with the weapon…." However, I would read "ranged" as the more specific rule. Since "make a ranged touch attack with the weapon" parses without any particular difficulty, I would go with that. From there, I would apply tripping exactly as written:

If your attack succeeds, make a Strength check opposed by the defender’s Dexterity or Strength check (whichever ability score has the higher modifier). A combatant gets a +4 bonus for every size category he is larger than Medium or a -4 penalty for every size category he is smaller than Medium. The defender gets a +4 bonus on his check if he has more than two legs or is otherwise more stable than a normal humanoid. If you win, you trip the defender.

You apply any bonuses or penalties that apply on attack rolls. In essence, a CMB roll is an attack roll.

Source: SRD

When you attempt to perform a combat maneuver, make an attack roll and add your CMB in place of your normal attack bonus. Add any bonuses you currently have on attack rolls due to spells, feats, and other effects

Thus you apply flanking bonuses, power attack penalties and even Weapon Focus(longsword) if you use it to make a disarm attack.