Yes, but it won't work like that
You can apply two Bend Luck features to a single roll, but they won't stack. Instead, you would take the 'most potent' one, which in the case of two positive increases is the larger of the two dies; essentially the roll of the d4 would be made with advantage.
This is because, according to the DMG errata (first page, right hand side), game features with the same name don't stack:
Combining Game Effects (p. 252). This is a new subsection at
the end of the “Combat” section:
Different game features can affect a target at the same time. But when two or more game features have the same name, only the effects of one of them—the most potent one—apply while the durations of the effects overlap. For example, if a target is ignited by a fire elemental’s Fire Form trait, the ongoing fire damage doesn’t increase if the burning target is subjected to that trait again. Game features include spells, class features, feats, racial traits, monster abilities, and magic items. See the related rule in the “Combining Magical Effects” section of chapter 10 in the Player’s Handbook.
Note as well that if Rico had an evil twin, Ricothree, who sought to make Bob fail the saving throw determining which is more potent is somewhat less natural-- you still take the highest rolled number but it now is important to determine whether that number is a bonus or a penalty: only one of them applies. If the same number is rolled the GM must determine whether a bonus or a penalty is more potent, all else being equal, and should they decide that there is no inherent difference in potency the resolution is entirely unclear.