I know United and Eurowings are partners, and interline baggage if it's on 1 ticket. I however have 2 separate tickets. The 1st leg is on United and the 2nd leg is on Eurowings connecting in London. The 2nd leg is within 24 hours of the first. Will I be able to get the UA agents at check-in in SFO to tag on the separate Eurowings segment onto the baggage? I know it wouldn't be a problem if it was a full *A partner, but as they aren't, I'm not sure whether this is possible. Thanks for any help .