Had spinal tap which resulted in a spinal headache. Headache has gone and I'm able to walk/stand for long periods. Am I safe for alcohol consumption?

Should be OK. To be completely safe, get in touch with the doctor who did the LP. The main concern might be whatever medical problem made the tap necessary. From the standpoing of the post-LP headache, moderate alcohol shouldn't be a problem. But don't tank up in a big way!