Space between treble and bass clef

In general you shouldn't need to increase the space for lyrics - that happens automatically. And indeed, there is enough space between the staves in the example you attached. The problem isn't the amount of space; it's that the lyrics are too close to the top staff in some systems, because of the notes on ledger lines.

You can globally lower all lyrics via Style / General / Page / Lyrics top margin. You can also adjust for a single system by selecting them (eg, selecting the measure, right click on lyrics, Select / All Similar Elements in Range Selection) and then using the Inspector.

But for the record, the space between staves of a grand staff are adjusted in Style / General / Page / Grand staff distance. It won't help here, though, because as I said, that's not the actual problem. Your lyrics would still clash with the notes below the top staff.