Went to a corporate store and spoke to a manager. He tried to add U200 and TMS4, no luck. He referred to the NBO (for FAN users/business users) but told me their hours were 8-5pm Central. It was 550pm but I thought I'd try anyway.
Long story short, because it was after hours I got connected to the regular Business CS (that you would get by dialing 611 on your phone if you have a FAN discount).
Rep there was very nice -- she flat out told me that free bonus minutes were not being given out anymore, so couldn't/wouldn't try applying U200 (frankly, it was my mistake -- I defined U200 for her without being prompted). I then gave her the codes for TMS4 and CLL2 and both added without issue (told her to take my $15 for 1500 off before adding TMS4). She was even surprised when it took. Seemed very willing to try these other codes. But, again, as soon as she knew the U200 was a bonus minute code, she didn't even try it.
She even went so far as to annotate my accound because she was concerned that the TMS4 showed up as "Text Msging 1500 B2B" that it would only apply to business to business user texts, not general SMS, so in her annotation she expressed this concern and conveyed that if for some reason I am charged for texts within my 1700 (1500+200) that reasoning was documented in the system to remove the charges. I had read earlier that this is how the TMS4 is displayed in the online account profile, so I didn't poke that bear.
She also explained that there is a back-end system that scours accounts each month and "removes" codes it thinks are not valid/should not apply to a particular account. This may explain why some people have seen codes disappear. Based on what I've read on this thread and elsewhere, I think this is pretty haphazard.
This was my 6th time trying for these codes so it was nice to get something. I am annoyed I couldn't get U200, but may try again tonight -- not sure if I should push my luck.