I can't find my source for that info, but from looking over the workouts again, the only time this discrepancy makes any substantial difference is with the Sunday ride in the Intermediate plan.

In which case, I'd do the 150 minutes instead of 90. (Going from a 60-70 minute ride during the week to a 90 minute ride on Sunday isn't much of a difference.)

For weekday rides, whether you're counting 12 second sprints, 3 minute intervals, or 10 minutes of Tempo, it won't make much difference if it's included within, or in addition to, 60 minutes of light riding.