If you interpret "tied to treason" loosely enough, absolutely. In early American politics under the First Party system, both parties were accusing each other of treason. The Federalists were accusing the Republicans, including later President Jefferson, of treasonous cooperation with France; the Republicans were accusing the Federalists, including President Adams, of treasonous cooperation with Britain. For good measure, each party was also accusing the other's leader of plotting to become a dictator or king.

Admittedly, these accusations weren't very credible - the Republicans did favor France over Britain, and the Federalists favored Britain over France, but neither went beyond that. However, as the two countries were in the middle of a lengthy war with each other, those accusations had some superficial plausibility to people far removed from Philadelphia, the capitol at the time.

I'm not aware of any President-elect who was actually, credibly guilty of treason, though. The closest I can think of was President Buchanan, who sat back and did nothing while Confederate sympathizers in his cabinet left US armories open to be raided - but he was about to leave office at the time, and never prosecuted for it. This's in part because treason is fairly difficult to commit. The Constitution defines it as "levying War against [the United States], or in adhering to their Enemies, giving them Aid and Comfort" - and "enemy" is defined strictly. For instance, even during the Cold War, no one was ever prosecuted for treason for aiding the Soviet Union, because we were not at war with them. Beyond the 20-Year Rule, one person was charged with treason for aiding Al-Qaeda, but his case never came to trial before his death.

However, if a President-Elect did commit treason - or any other crime - he could be indicted and tried in a normal court just like any other criminal. Hopefully, Congress would also impeach him promptly after his inauguration.