Ok for the sake of argument lets break this down in a systematic manner...
Football is huge in the US... That said, the Bears are probably not among the top recognized teams in the nation. Let's say they're in the 2nd tier of teams in terms of recognizability. Lets Assume 75 percent of Americans know them 300 million * 75 = 225 million Americans are 'aware' of the Bears.
Tiesto isn't as huge in America, in fact his notoriety is limited to those under the age of 30 - for the sake of argument lets say that 5 percent of Americans know tiesto - 300 * 5 percent = 15 million Americans
In Europe, Electronica/Progressive is easily the most popular music played in nightclubs and such. It's equivalent in the US would probably be a hybrid between Light Rock/Alternative (in widespread appeal) and R and B (in terms prominence/airplay/club play), Tiesto, in other words would be like Nickelback and 50 cent combined in terms of widespread appeal and airplay in nations with heavy european influence. Definitely not amongst the most recognizable of all time, but pretty well known amongst those who pay even the slightest bit of attention towards current pop culture. The Eurozone has ~320 million people and countries that peg the currency to the Euro add another 160 million individuals to this number. 480 million * 50 percent awareness rate = 240 million.
American football is definitely less followed in Europe... For the sake of argument lets say 5 percent of people in the Euro-influence zone follow American football (480 x 5 percent = 24 million) and 75 percent of those people are aware of the Bears (24 mil x .75 = 18 million).
So now lets sum up awareness numbers in these two large home markets for both of the parties involved
Awareness Chicago Bears in the US - 225 Million
Awareness Chicago Bears in the Eurozone- 18 million
Total US/EuroZone Awareness = 243 million People
DJ Tiesto Awareness US - 15 million
DJ Tiesto Awareness EuroZone - 240 million
Total US/Eurozone Tiesto Awareness - 265 million.
These are baselines... now for the rest of the world (ROW), we should proceed with the following assumptions:
3/4 people that are aware of American football know the Bears
3/4 people that are follow trance music know DJ Tiesto...
With those assumptions held, it comes down to the following:
Outside of the US and Euro, what is more popular American Football or Trance/Electronic music... Answer that and you have the answer to the question posed by the OP