I'd say that most of us are probably going to be less familiar with the RIAS than other IQ tests so we may not be as much help. What little I do know about the RIAS is that it is a very short test. My youngest was given it along with the WISC when she was about 8. She is 2e and both the WISC and the RIAS had wild variations within the subtests. Her composite score could not be figured at all on the RIAS b/c the scores were so divergent. That does not appear to be the case on your test although I'm wondering if you have the test scores for the verbal/nonverbal parts of each of those subtests.
If I recall correctly, each of those indices (VIX, NIX, etc.) have two scores (verbal & nonverbal) that feed into the total score. That might give more info as to whether that wild variation that one would likely expect for a 2e student is there but hidden by the composite subtests being the average of the two.
The percentages you posted for the WJ sound about right to me and the Academic Fluency should be about the 97th percentile. There should also be an Academic Applications or Academic Skills score which is more of a composite. However, when you are dealing with big spread btwn tests, those types of scores are less meaningful.
I certainly have seen kids who have gifted achievement scores and who read above grade level by a good bit who do not have matching IQ scores. Those kids usually like to read a lot and don't have any learning disabilities that prevent them from reading frequently.
Remind us, what was the purpose of this testing? IQ tests are just so expensive that I'd hate to say that you should have a more well known one done, but it would help sort out whether the RIAS was a low ball measure for you. The other issue that you're going to run into if you are at the upper age limit for many of the tests (WISC, for instance) would be that it is harder to show what you know when you are near the top age for which the test is normed.
How about doing something like taking the practice Mensa admission test (you can do that at home) and seeing how close you come to their cut? They have a free online "workout" that will tell you how well you did at the end:
http://www.mensa.org/workout and a home test that will give you some idea as to whether you'd be likely to qualify:
https://www.us.mensa.org/join/mht/