If I change the string tension for .009, .042 to .010, .046, do you think the trus rod will need any adjustment? The guitar has a wilkinson 'floating' bridge thing so surely that will take some of the extra tension?

Nope, just a tiny bit of adjustment that you can just neglect it.

And floating or floyd rose, the bridge doesnt take tension that way. Its balanced by the spring tension and has nothing to do with the neck being bowed in any such ways.
"Play with your ears" - Yngwie Malmsteen, Paul Gilbert
Thats what she said...
Sorry, but do you mean the difference is so tiny that don't need to do it?

EDIT- doesn't matter, i understand now