I take both, have taken them for years for fibromyalgia and muscle spasms. Neither ever did anything to improve or worsen my GERD. (I had the surgery so don't have reflux anymore.)
Valium is a very good muscle relaxant, among other uses. Tramadol helps with some types of pain, also raises serotonin level, so it's got a good side effect of elevating mood, for me at least.
Do tell your gastroenterologist if you are taking these medicines, or tell the prescribing doctor you have GERD. I wouldn't stop taking these medicines though, unless there is a medical reason.