Work Features can be used with the pattern tools in the Part environment, but not at the Assembly level/environment.
Sometimes it is useful to draw axes and points at the assembly level and use those for a pattern, rather than features/components only.
For example, if you do not want to have holes made at the assembly level, but want to pattern bolts going through SOME (not all) of the holes patterned at the part level, you could simply pattern axes through some of their centers (starting with any hole), then use those to pattern your bolts. Right now we are limited to copy a pattern from the part level onto the assembly level, then suppressing/deleting additional unwanted occurrences.

