Grow bag compost

It's just about time for the big plant pot shuffle so am now clearing out the greenhouse.  This is my first year growing tomatoes and cucumbers, much to my surprise, they have done really well.  

I understand that I can reuse the growbag compost (decanted into pots for growing plants) by spreading it around the borders.  However, I remember reading somewhere once that tomato feed was alkaline rather than acidic.  Therefore, if spreading on the borders should I avoid areas where plants that prefer conditions neutral/acidic grow?  Will there be much trace of the tomato feed in the compost.  I've spread compost from pots of annuals around the borders before with no consequences.  Am I bothering about nothing? 

Thanks, I hope this isn't too much of a stupid question.