Can anyone explain to me the difference between a Bash patch and a Tes5 patch and which is better to use?

Thanks

See this thread, it has a pretty detailed discussion of the process. I will close this thread so any further discussion can take place in the linked thread.

http://www.gamesas.com/topic/1501035-what-is-better-for-creating-merge-patches/

Basic conclusion, unless you are real familiar with the structure of mods, then Wrye Bash is best for this.