The Presidential Plus card from CO earns flexible EQM (I believe 1k EQM after every $5k of spending) that can get you elite status up to CO Platinum (1K is not obtainable from only credit card spend). The Mileage Plus Select Visa Signature card earns 1 EQM for every dollar spent on United (up to 5k per year).

The OnePass Plus/Mileage Plus Explorer/Various Delta cards can get you various elite-like perks on their respective airlines.

Honestly, if you have three alliances to choose from (and your flying is that spread out), you would be much better consolidating your travel onto a single airline.