I don't have the magic item description. Is giving you that bonus jump the only thing they do?
There is no language I can find in Basic saying that if you have multiple bonus actions to choose from, you may use your regular action to enact one of them.
I might well rule that it was okay, at my table. But it isn't explicit in the rules that you can do it.
I suppose I should have included the word "hypothetical" as-in hypothetical boots of striding and springing may give a bonus action choice of jump 10'. I haven't seen any magic items yet. My interpretation revolves around the language used: "...must use a bonus action on your turn to cast the spell, provided that you haven’t already taken a bonus action..."
So it must be a bonus action unless you've already used it. If it were limited to always requiring a bonus action that is much more simply written.