For this one, I would trust the elliptical all the way! Here's why...
First, I have found internal errors with Apple's calorie calculations and discrepancies between Apple's calculations and other external exercise machines and fitness devices. Furthermore, others have found discrepancies, similar to yours, between Apple and elliptical machines. In general, I do not trust the AW calorie calculations if I have another source.
Second, the AW has you at 12 calories/minute at an average HR of 149. That is a pretty stout HR, but 12 cal/minute is a seriously intense workout. The elliptical has you at about 7 calories/minute, which is in line with what most people are likely to do.
Things to check that could make one more accurate than the other:
- That they both have your accurate bio-metric data (age, weight, height, sex, etc.)
- That the elliptical had your HR throughout the workout