PLL clock question

When going between related clocks, the default relationship is the faster clock's period(6.25). If you want it to be 25ns, then your setup multicycle should be 4, like it is. If you want the hold relationship to remain at 0ns, then your multicycle -hold value should be 3. (The default hold relationship follows the setup relationship. I have a description of this in the TimeQuest User Guide on alterawiki.com).

What you currently have is a 25ns setup relationship and 12.5ns hold relationship, which means the router has to add at least 12.5ns of routing delay to meet hold, so your timing should become worse. Just change the multicycle hold to 3 and you should be fine.