It is a known fact of SP SMAC that the AI dos generally not build enough bases, preferring instead to concentrate on infrastructure (even that it doesn't do very well). Even switching the AI to growth does not really have the desired effect, because it tends to concentrate on actual population growth, rather than territory expansion.
Maybe the AI associates territory with power? I have noticed that Santiago is reasonably proficient at expanding, although this depends heavily on the circumstances of course.
OTOH, one of the reasons the AI fails to grow is because of its tendency to 'rush' at other factions, hampering not only the enemy, but themselves as well.
Maybe change aggression to -1, and settings to power? I haven't actually tried it yet, maybe I will tomorrow when I can be bothered, but it would seem logical (for me anyway

).