The UK is not a signatory to the Schengen agreement, so UK visas can't be used to enter other countries.
Your wife must obtain a Schengen visa. To do so, she must write to this address:
Spanish Consulate General,
Visa Appointment, 20 Draycott Place
London SW3 2RZ
She should enclose a photocopy of the relevant pages of her passport. (These are the 'personal details & photograph page together with the page where the UK visa is entered). She should also state the intended date of travel and enclose a stamped address envelope.
Within a week or two, your wife will receive a reply. This will give details of the date and time of her appointment at the consulate in London. The letter will also include the application form (or you can download it from the link below).
When your wife attends for interview, she must take the completed application form and a whole load of other documents (including both your passports). For details,see the link below.
From the time of the appointment, visa applications for holders of Phillipines passports usually take 2 to 3 weeks to process.
This information has been summarised from here:
http://www.conspalon.org/indexeng.html
(Go to 'Services > Visas' to display the relevant information).
Chris