Originally Posted by
Flyingfox
If the other two flights are on the same day as your arrival flight from IAH-FRA, I think you would have access since you have a boarding pass showing arrival on LH in F on that day.
Someone please correct me if I'm wrong!
If LX applies the same entry rules as LH then you'll need to be connecting on to a service operated by LH group and affiliates in order to get F lounge access in ZRH. LX may be more lenient, but that's the story with LH in FRA/MUC.
Let us know how you get on, always good to get an update...