The first expression "בר שמתא הוא" seems to be "bar shamta hu" i.e. he warrants excommunication/ostracism.
See, e.g. Jastrow:
שמתא, שמתא, שמתא f. (preced.) [desolation,] 1) curse, ban. Targ. Y. Gen. XLII, 37. Targ. Y. Num. XXI, 24. Targ. Cant. II, 16. -- M. Kat. 17a ש׳ מאי what is (the etymology of) shammta?h Rab said מיתה שם there is death; Samuel said, יהיה שממה (Ms. M. שמה; Ar. שם תהא, read; תהא שמה) he shall be (be thou) a desolation. Ib. בש׳ גברא האי ליהוי that man (thou) be excommunicat- ed. Ib. 16a וכ׳ עליה ש׳ חל לא (masc.) the ban has not yet rested on him thirty days. Ib. וכ׳ ש׳ דחיילא עד (it cannot be raised) before he has been under the ban thirty days. Sot. 5a ביה דלית ובש׳ ביה דאית בש׳ he (the scholar) in whom there is pride deserves excommunication, and also he in whom there is no pride at all. Kidd. 12b Rab ordered to be lashed וכ׳ ש׳ דחלא על him who allowed excommunication (for contempt of court) to rest on him thirty days (and did not submit to authority). B. Mets. 70a דרבנן ש׳ עליה מקבל ולא Ms. M. and does not bring upon himself the ban of the Rabbis (but obeys their summons); a. fr. - 2) י h. חרם, accursed oyect. Targ. Y. Deut. XIII, 18. -- Pl. שמתין. Ib. VII, 26, v. שמיתא.
See also, e.g., here and here for possible distinction between shamta and nidui.
- The latter expression "עד דמייתי ליה וקיימי בבית דין" seems to mean: "until they bring him and they stand in court".
See Jastrow:
אֲתָא, אָתָא II ch. (b. h. אתה, אתא; sec. r. of אוֹת I q. v.) [to join,] to come, to arrive; to occur to. Targ. Gen. XIX, 9; a. fr.—Y. Peah III, 17ᵈ bot. אתאי עובדא וכ׳ the case came before … Gen. R. s. 68 (ref. to Gen. XXVIII, 11) א׳ שמשא the Sun (Jacob) has arrived. Snh. 98ᵇ יֵיתֵי ולא איחמיניה he (the Messiah) will come, but I do not desire to live to see him (to pass through the trials preceding his arrival).—תֵּיתֵי לי ד־ may it come home to me that I did—, i.e. I believe to have merited divine reward. Meg. 28ᵃ; a. fr.—ייתי עלי דלא may it come home to me that I did not—; a formula of assurance, surely, indeed. Y. Ber. II, 5ᶜ bot.; a. fr.; (v. יבוא עלי, s. v. בּוֹא).—Y. Shebi. VI, 36ᶜ top ייתי ד־ (sub. עלי).—Imperat. תָּא (Y. אִיתָא). Gitt. 57ᵃ, a. fr. תא חזי; Y. Dem. VI, 25ᵇ top איתא חמי; in Bab. usu. תא שמע (abbr. ת"ש) come and see, come and hear, i.e. I will prove it.—אַתְיָא כ־ it comes like, i.e. it is in accordance with the opinion of.—Y. Naz. VI, 54ᵈ bot.; a. v. fr.—וַתְּיָיא = ואתיא. Ibid.ᶜ bot. ותייא כהדא דתני חזקיה (ed. Krot. incorr. ותניא) תִּי.—Y. Keth. IV, 28ᵈ top ותאיין וכ׳ (read ואתיין) and those differences of opinion correspond to …—אתיא פקידה פקידה the expression pakad occurs in two Biblical passages, אתיא זכירה זכירה and the expression zakhar occurs in two passages, i.e. draw an analogy between the respective Bible laws in which the same expressions are used, so as to cast a light upon each other. R. Hash. 11ᵃ; a. fr. [אתא נסיא Y. Meg. II, 73ᵇ, a. e., read אֲתָאנַסְיָא q. v.] [Targ. Y. II, Deut. XXXIII, 16 יַתְיַן, 3rd pers. fem. fut.]
Af. - אַיְתִי, אֵיתִי, , אַיְיתִי to bring, carry, cause to come. Targ. Gen. IV, 3; a. fr.—מנא תיתי (מהיכא, מנן) whence wilt thou bring (evidence), how will you prove it? Y. B. Mets. III, beg. 9ᵃ; a. v. fr.—מַיְיתָה, מַיְיתִי, מֵיתֵי bringing, to bring. Y. Peah I, 15ᶜ top בעי מ׳ וכ׳ he desired to bring it to them. Ib. לא יכילת מייתותי׳ I cannot bring it.—לַיְיתֵי, לֵיְתֵי let him bring. Sabb. 109ᵇ; a. fr.—לאַיְתוּיֵי, לַאֲתוּיֵי (cmp. אֵת) to bring in, to include, opp. לאפוקי; v. אַפֵּק. לא׳ מאי what is to be implied (in addition to what is explicitly stated)? Tem. 2ᵃ הכל לאי׳ מאי what does hakkol (all) come to imply? a. fr.—Haf. הַיְיתִי same. Dan. V, 13; a. e.
Ittaf. - אִתֵּיתִי (אִתּוֹתִי, אִתַּתִי) to be brought, offered. Targ. Gen. XXXIII, 11. Targ. Lev. XIII, 2; a. e.
