Yes I did that and it says 50% for C on UA. My feb C ticket got it but the March and onward no. It is C booking code and it is listed in my MP account as such.

Cut and paste from MP statement:

Here is a listing from Feb:

UA C Class 938 ORD to LHR

* 8,895
* 3,953flight miles
* 3,953bonus for elite members
* 989bonus for booking code

Here is a listing from Mar:

UA C Class 949 LHR to ORD

* 7,906
* 3,953flight miles
* 3,953bonus for elite members
* 0bonus for booking code

I'm also confused why it's only 25% in Feb and nothing in March when it seems it should be 50% for both.

OK it might be that the MP account fare listing is wrong rather than the miles credited. I just looked up the ticket receipt and it lists the above flights as respectively D and Z class rather than C class as stated in the MP account. Z gets no fare bonus and D gets 25% which would explain the miles credited. They both get 50% EQM however and apparently that is not listed and can be different from the fare bonus. It would be helpful if UA MP states the correct booking code when it credits miles.