The pair - signed for an estimated £14 million in January - combined for Hull's opener on 12 minutes, Long converting after racking onto Jelavic's flick-on, only for Paulinho's second-half effort to snatch a draw for Spurs.
Croatia international Jelavic failed to net his first goal for the club, though it was not for a lack of trying as he rained several efforts in on Hugo Lloris' goal, hitting the post and finding the Frenchman in fine form.
Hull's top scorer this season remains Robbie Brady, who scored three goals in the opening six games of the season, but former Sunderland boss Bruce believes he may have struck gold with his new strike partnership.
"I thought Long and Jelavic were a handful all afternoon," Bruce said.
"I am convinced they will give us the platform which we will need to make sure we stay in this division.
"They are both good players who have been round the block a little bit and know what it's all about.
"Although the partnership is only in its early days, I think they will certainly be a threat for anyone who plays against them."
