Originally Posted by
drewguy
You can get these benefits even with separate PNRs, though, with a call. The only drawback is that the people on the PNR without the elite will not be able to change their E+ seat assignments themselves - you'll have to call in.
Whilst this might be true for E+, it's nowhere near as clean - as others have said it'll need to be done over the phone, and sweeps/equipment changes/etc will have everyone back in E-.
For some of the benefits (eg, checked baggage) it's officially only for those on the same reservation. You might get a check-in agent to bend the rules occasionally, but probably not for an additional 6 people...