Your 81 on the course rated at 72.6/134 is almost two shots better than the 79 on the 69.8/117 course. It is not unexpected to score better on "easier" courses. In your handicap calculations the differential for the 81 should be something like 7.1 and the 79 should be about 8.9. Both of those are much better than your handicap so congrats on the good scores. To know if your handicap "travels well" you should play a course with similar course rating and slope to your home course.