Two names, one page, one session
If the session has a second speaker, give them the same treatment: their own name, title, photo and biography block, each with a coverage line that says which part is theirs. A page can hold several speaker sections, and the pair reads far better when both bios say what half of the hour each one is responsible for rather than describing two identical careers.
One limit worth knowing before you write anything. A page carries a single live session, so the biography describes the person standing behind this particular date and time. Write the bio, publish the page, and change it afterwards if you like — the address holds while the text behind it can move, so a speaker whose title changed last month is a two-minute correction rather than a reprint.