Juve will finish top of Group D while Spurs take second place in Group B, so the two teams could face each other in the round of 16.
Bonucci told Sport Mediaset (h/t Football Italia): "If I need to pick a team to avoid, I would say Tottenham. Mourinho may give them something extra in certain games. A lot can change between now and the last 16, but with this change Tottenham are back on track, with all respect to [Mauricio] Pochettino."
The Bianconeri, who reached the Champions League final in 2015 and 2017, have been one of the competition's stronger performers in the group stage this season:
Since drawing with Atletico Madrid in their opening fixture, they've picked up four consecutive wins, cementing top spot with Tuesday's 1-0 victory against the Spanish side.
"It may have seemed easy, but it never is," Bonucci added. "We have had a good run and achieved our first goal."
Pochettino guided Spurs to the Champions League final last season, in which they lost 2-0 to Liverpool.
The manager was replaced by Jose Mourinho last week after a poor start to the campaign.
Spurs beat West Ham United 3-2 in Mourinho's first game in charge, and they came from behind to beat Olympiacos 4-2 on Tuesday.
Youssef El-Arabi and Ruben Semedo put the Greek side 2-0 up inside 20 minutes. Dele Alli pulled one back on the stroke of half-time, and second-half goals from Harry Kane either side of a Serge Aurier strike gave Spurs the win (U.S., UK only respectively):
Mourinho opted to substitute Eric Dier for Christian Eriksen after just 28 minutes, which football coach and former player David Preece thought was a shrewd move:
Spurs may not be the best team in the competition, but they have enough talent in their side to beat anyone on their day, so they're a threat in the knockout phase.
Bonucci's fear of Mourinho is understandable, too. The 56-year-old has won the Champions League twice—albeit he last did so in 2010—as well as the UEFA Cup and the UEFA Europa League, so he's got plenty of experience in guiding teams to European glory.