Scott Kilday left MJM International when he found a listening device hidden in artificial flowers. The bug had been set up amid fears Mr Kilday was planning to quit to work with Ms Mone's ex-husband Michael.
Mr Kilday, who had the role of operations director at MJM, took the firm to an employment tribunal. He lodged a claim for unfair dismissal and was also seeking £25,000 in shares he claimed he had been denied.
After a hearing in Glasgow last September, judges found in favour of the 35-year-old in relation to the unfair dismissal claim. Mr Kilday received £15,920 in compensation after the tribunal judge said MJM's decision to plant the listening device was likely to "destroy or seriously damage" Mr Kilday's trust in his bosses.
His former employers, now called Ultimo Brands International, said they were "delighted to have won the main aspect of this case relating to the shares".
A spokeswoman said: "With regards to the secondary case, we are in discussions with our lawyers and insurers to review our options to appeal."
Mr Kilday, who works for a rival firm set up by Mr Mone, said he can "walk away with his head held high". He said: "At the end of the day, it's not about the money, but standing up for what's morally correct and not being bullied into keeping quiet."