Your first suggestion is the one to use here. [simbraille]_..,ta# d'h@ote or .prix ._.fixe[/simbraille]
The entire phrase (more than 3 words) is bold, so it gets a double bold at the beginning and the closing bold before the final word.
The final two words are both in italics, so each one is preceded with italics. These final two words are also in bold and the addition of the single italic indicates to the braille reader the same thing that the print reader sees, that in addition to being bold, those final two words are also each in italics. That final word was preceded by the closing bold in the first place and the addition of the single italic to it also happens to be the same as bold italics, which is what it is.
The braille reader also sees that the text that follows this phrases has no font attributes.
What may be confusing is the the combination of the single italics with the closing bold happens to be the same sign as just a single bold italics, which would have been used if the other words in the phrase were not bold.