etiquette for bring your own wine.
First, make sure you ask if BYOB is accepted when the reservation is made. To avoid any later 'issues' - also ask how much the corkage is.
You don't need to tell anybody what wine you plan on bringing (although a caution here - some places will not let you BYOB if the same wine is on their own list; check their website - if the winelist isn't posted then you have a potential comeback argument).
You will be charged tax on the corkage fee. You can (if it is a 'rare' wine) offer a taste to the server (or sommelier), but this is not required. Most (all?) servers would prefer that your gratuity reflect the service e.g. base the tip on what the bill WOULD have been if you had ordered a 'moderate' wine from the winelist. e.g. if you would normally tip 15% then consider tipping 20% (or more) or try adding maybe $50 to the bill (notionally) and tipping 15% on the total (Note: your percentages may differ). And then round the amount e.g. if your calculation comes to $29 (say) then leave $30.
Corkage at Globe has changed over the past 6 months - first down, then up again, so I don't know what the current fee is. But ALWAYS play it safe by asking before you go. And incidentally, Globe has a pretty good winelist and their prices are pretty good by Toronto standards.