An previous subordinate had hired direct from college and basically mentored and raised in the company, while she was unable to travel the initial 2 years (limited and job required 50-60% travel) because of passport and later obtained another passport. Which we sacrificed, patient and fought even unpaid leave for her to obtain. Then 1.5 years after obtaining passport, being fully trained and getting to know market she transferred to another division without the other division or HR even approaching me for feedback (she told me had applied) but her sudden hire was a surprise. Her transfer announcement was mentioned many things she did not do on our division (gain accounts, conversions, etc) as she could hardly travel. Now in other division she is very close to her manager, travelling for weeks at a time, always spotted sitting next to each other on plane. During work hours they are in office together nearjy 75% of time. They arrive and leave at the same time (leave together but arrivals just little bit off) and park right next to each other even though we have randon spots access to anywhere in garage. While traveling they were returning in same taxi together (he is married but not her). She was promoted even though not making budget since moved to other division after only 1 year (now 4 years in other division) and last year 22% under budget. Another time he was spotted driving her car with her to an local work related exhibition and they returned around 8-9 pm in same car. This is also out of normal for culture in the area (middle east although a more open UAE). It is obvious preferential treatment and may be even affair, she also has given him expensive presents. It is unethical favoritism but since he is manager of division and she 'high potential' nothing seems to be done. Should I report this (anonymous) via our ethics hotline as others feel the same way and maybe know but maybe afraid to report.

Always report unethical behavior to the ethics hotline. It would be a good idea to first get irrefutable evidence so it is not simply hearsay.

Thank you she was recently promoted although not making budget her initial.years and last year 20% below budget which in normal circumstances should site a warning but instead she was promoted to a higher position in the company.

Do you have irrefutable evidence of an affair? Could they provide innocent explanations of why they arrive and leave together, and sit next to each other on planes?

If you are sure that anyone else would be warned for being 20% below budget and would not be promoted, you should report to the hotline and suggested. In other words, it's up to you to decide whether the evidence is strong enough.