TiddlyWiki tends not to use escaping in the traditional manner of a programming language. My original thinking was that escaping was complex and often caused problems for experienced programmers, and so it wasn’t a good match for TiddlyWiki target users. The workaround is to define a separate function or procedure containing the text [[JeremyRuston]], and then reference that within the filter.
One of our long term goals is to figure out a syntax for defining local variables within a filter which will make things like this a bit easier.