Ok, so there was some confusion over what I was trying to do.
Initially, I was trying to add h2 tags around board names on the main page, which I did with the help of Simon.
Next, I was trying to add h2 tags on the inner board pages around topic titles. For instance:
"Google's Birthday: 15 Years Old!"
Tech Forum
I eventually figured it out. It was located in the threadbit and not the forumdisplay template, which is strange to me but I got it working.
@tbworld
Yep, you were right about the Javascript not being readable by search.