Trust this computer - what is shared?
Unless you explicitly backed up your iPhone to your work PC using iTunes (or ran some other type of program like Macroplant's iExplorer), you're probably fine. Tapping the "Trust" button does allow a computer to access an iPhone's information, but doesn't initiate any particular kind of access.

For more information, see 'Trust This Computer' alert on iPhone, iPad, or iPod touch.

Let me know if this helps.