I would advise against doing anything to get CO or UA Bonus miles unless you are very familiar with Starnet Blocking.

It's a UA only phenomenon that really - well it really stinks and makes their miles worth a LOT less than competing *A carriers.

What I usually experience is this on my routes - domestic Business Class flying a route that ONLY US AIR serves direct:

UA: "Sorry No Availability" (They can get you there but with 1 or 2 stops and higher fees and higher mileage though)
US: 50k miles less 5k for having their credit card = 45k
AC: 40k miles

UA Miles have become useless to me and I give them away to family members who have to fly 3 stop trips in order to use them.

Please don't risk getting caught up in *net blocking - it really stinks.