反华 literally means "anti-China"
Example:
Anti-China protest
反华示威
排华 is similar to 排外 (which is to discriminate against other races (xenophobia) in general) but because 外 is changed to 华 here, it specifically refers to Chinese/China.
Example:
Why do the XX discriminate against China/Chinese people?
(某)国人为什么排华 ?
Hope that helps