I see 2615 as a subset of 1490. 2615 includes just JS client-side error tracking services whereas 1490 includes non-js tracking (Crittercism & BugSense are for mobile apps, for example) and potentially could include self-hosted tools.
Though there’s a question of whether 1490 is useful in its current form - whether it’s useful comparing mobile app tools against webapp tools even if they’re in the same product category.