I have never observed a Maso AI with bonus range. They get to Controlled Gravity quickly, but until they do, they have the same range as I do, unless they have extended it with a starbase.
You have to watch, though. The baseline range is longer on larger maps. Probably the best map size to test with is Huge. AI's far enough away, but not too far. You get to see situations where a system is at first out of their range, then within their range. You have really got to hustle to make sure to get your fair share in the land grab, because the combo of early starbases and insanely fast early game research means time is not on your side.
I'd tend to concur with the notion that it is likely an early starbase and legitimately extended range, to explain AI's traveling far to settle. Also keep in mind, they have always sent extra colony ships on low fertility maps, so after settling a system that extends range, they are immediately ready to make the next leap.
- Sirian