Hi Beadipo975,welcome to the forum.

Although many resins will bond fairly well to glass I would probably notrecommend coating the glass itself, glass will age better than any resin willdo, over many years resins will gradually yellow and could potentially peelfrom the smooth glass surface, so in-fact you may end-up in years to comeregretting coating over the glass. The grouting is likely to be mush lessresilient that the glass and you may well improve its life-span with a coat ofresin. I would advise using the EpoxyCoating Resin this can be applied with a fine brush over the linesof the grout, pain-staking work but it would seal and protect very well. 

I hope this helps.